PubMed Help

PubMed Help

Tutorials

PubMed comprises over 22 million citations for biomedical literature from MEDLINE, life
science journals, and online books. PubMed citations and abstracts include the fields of
biomedicine and health, covering portions of the life sciences, behavioral sciences, chemical
sciences, and bioengineering. PubMed also provides access to additional relevant web sites
and links to the other NCBI molecular biology resources.

PubMed is a free resource that is developed and maintained by the National Center for
Biotechnology Information (NCBI), at the U.S. National Library of Medicine (NLM), located
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at the National Institutes of Health (NIH).

Publishers of journals can submit their citations to NCBI and then provide access to the full-
text of articles at journal web sites using LinkOut.

For a brief overview of searching PubMed, see the Quick Start section.

FAQs
• How can I get the full-text article? Tutorial

• How do I find consumer health information about a disease or condition?

PubMed Help

• How can I export citations to my citation management software program?

• How do I create a link to PubMed?
• What can I do about system error messages or typographical errors?
• Why is the link to the full-text not working?
• How can I save my search and receive an automatic email update?
PubMed Quick Start
Section Contents
• How do I search PubMed?
PubMed Help

• How do I search by author?

• How do I search by journal name?

• How do I find a specific citation? I have some information such as the author, journal
name and the year the article was published.
• Is there anything special for clinical searches?
• How do I find systematic reviews?
• How do I search for medical genetics information?
• Can you explain the search results?
• How do I display an abstract?
• How can I get a copy of the article?
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• How can I save my results?

• I retrieved too many citations. How can I focus my search?
• I retrieved too few citations. How can I expand my search?
• I’m not finding what I need. How does a PubMed search work?
•
PubMed Help

Is there a guide to NLM resources for MEDLINE/PubMed?

• I need further assistance and training.

How do I search PubMed?

1 Identify the key concepts for your search.

2 Enter the terms (or key concepts) in the search box.
3 Suggestions will display as you type your search terms. Click Turn off to temporarily
disable the autocomplete feature.
4 Click Search. Click here to run this search in PubMed.
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Example

What role does pain have in sleep disorders?

The key concepts are:

pain

sleep disorders

How do I search by author?

Enter the author’s last name plus initials without punctuation in the search box, and then click
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Search.

Example

Watson JD

Lederberg J

Click Advanced to use the search builder, and then select Author from the All Fields menu.
The author search box includes an autocomplete feature.
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Example

To search for citations to articles written by Bonnie W. Ramsey about gene therapy for cystic fibrosis enter the following
search terms into the search box:

cystic fibrosis gene therapy ramsey bw

Example

Full author names may be searched for citations published from 2002 forward if the full author name is available in the
article:

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Joshua Lederberg

Garcia Algar, Oscar

If you only know the author’s last name, use the author search field tag [au], e.g., brody[au].
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If an author name includes only stopwords, use the author search field tag [au] to search in
combination with other terms, e.g., just by[au] seizure.

How do I search by journal name?

Enter the journal name or abbreviation in the search box.

Example

To search for articles about drosophila in the journal Molecular Biology of the Cell enter the following in the search box:

molecular biology of the cell drosophila

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Click Advanced to use the search builder, and then select Journal from the All Fields menu.The
journal search box includes an autocomplete feature.

How do I find a specific citation? I have some information such as the author, journal name
and the year the article was published.
Enter the information in the search box and the PubMed citation sensor will automatically
analyze the search for citation information.

Alternatively, use the Single Citation Matcher to find citations with a fill-in-the-blank format:
1 Click Single Citation Matcher from the PubMed homepage.
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2 Enter the information you have in the fill-in-the-blank boxes.

3 Click Go.

Is there anything special for clinical searches?

From the Clinical Queries page you can search by a clinical study category, find systematic
reviews and run medical genetics searches.

Clinical study category

The clinical study categories use built-in search filters that will limit retrieval to citations to
articles reporting research conducted with specific methodologies, including those that report
applied clinical research. To find citations for a specific clinical study category:
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1 Click Clinical Queries from the PubMed homepage or from the advanced search more
resources menu.
2 Enter your search terms in the search box, and then click search.
3 You may then change the category or scope, if desired.
Example

If you are researching the clinical aspect of gene therapy for cystic fibrosis, from the Clinical Queries page, select the
category “Therapy” and the Scope “Narrow” and enter the following search terms in the search box:

cystic fibrosis gene therapy

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How do I find systematic reviews or medical genetic searches?

In PubMed, systematic reviews cover a broad set of articles that build consensus on biomedical
topics and medical genetics find citations related to topics in medical genetics.

Systematic Reviews is available on result sets as a filter under article types, as well as a selection
on the Clinical Queries page.
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1 Click Clinical Queries from the PubMed homepage or from the advanced search more
resources menu
2 Enter search terms in the search box, and then click Search.
3 For medical genetics, change the search topic, if desired.
Example

If you are researching systematic reviews on inhalation therapy for pneumonia from the Clinical Queries page, enter the
following search terms in the search box:

inhalation therapy pneumonia

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Example

To find information on sickle cell anemia and genetic counseling from the Clinical Queries page, enter the following search
terms in the search box, and then choose genetic counseling from the topic menu:

sickle cell anemia

Can you explain the search results?

PubMed search results are displayed in a summary format, see the anatomy of search results
page below.

Citations are initially displayed 20 items per page with the most recently entered citations
displayed first.
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You can mouseover a journal’s title abbreviation to display the full journal name.

Anatomy of the Summary Results

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How do I display an abstract?

Click the title of the article to see the abstract. “No abstract available” is indicated on citations
without an abstract.

How can I get a copy of the article?

Tutorial

PubMed search results do not include the full text of the journal article. However, the abstract
display of PubMed citations may provide links to the full text from other sources, such as
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directly from a publisher’s web site.

The full text journal site may require a subscription although access may be available through
your local medical library. In addition, online journals sometimes provide free access. Consider
visiting your local medical library if there is not an online copy available.

For more information on obtaining the article, see How to Get the Journal Article.

How can I save my results?

There are several ways to save PubMed search results including using the Clipboard to save
citations temporarily and My NCBI Collections to save indefinitely.
1 Click the check box to the left of the citations you want to save.
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2 From Send to, select Clipboard.

3 To display the items in the clipboard, click the Clipboard items link.
For additional information see Saving Citations Temporarily using the Clipboard.

For other save options, see:

• Saving and Managing Searches
• Creating a URL to Bookmark Your Search
• Saving Citations as a Text File

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• Exporting Citations to a Citation Management Program

I retrieved too many citations. How can I focus my search?

Tutorial
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To limit the number of search results:

• Replace general search terms with more specific ones (e.g., search for low back pain
instead of back pain).
• Add additional terms to your search.
• Use the sidebar filters to restrict your results by publication dates, species, article types,
etc.
• Click manage filters in the Filter your results portlet to change your My NCBI filter
selections.
Example

If the search pain sleep disorders retrieves too many citations consider adding more specific search terms to focus your
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results, such as facial pain sleep disorders.

I retrieved too few citations. How can I expand my search?

• Click the Related citations See all link for a relevant citation to display a pre-
calculated set of PubMed citations closely related to the article.
• Remove extraneous or specific terms from the search box.
• Try using alternative terms to describe the concepts you are searching.
Example

If your search, facial pain sleep disorders, retrieves too few citations consider removing search terms to broader the search
and retrieve more citations such as, pain sleep disorders.
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I’m not finding what I need. How does a PubMed search work?
PubMed may modify your search terms to enhance your retrieval.

To see how PubMed modified your search, consult the ‘Search details’ box displayed on the
results page and click the “See more…” link for further information.

For additional information, see How PubMed works: Automatic Term Mapping.

Example

If you search for cystic fibrosis by its abbreviation cf the cf search retrieves some citations that do not discuss cystic fibrosis.
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To see why PubMed retrieved these citations, consult the Search details portlet to see that PubMed translated cf to search
for citations about cerebrospinal fluid or cf.

I need further assistance and training

Contacting customer support
• E-mail the PubMed Help Desk
• Call the NLM Customer service desk: 1-888-FIND-NLM (1-888-346-3656)

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Other NLM publications

• Tutorials
• Distance Education Resources
• NLM PubMed Training Manuals
•
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NLM Technical Bulletin

Search Field Descriptions and Tags
Affiliation [AD] Investigator [IR] Pharmacological Action [PA]
Article Identifier [AID] ISBN [ISBN] Place of Publication [PL]
All Fields [ALL] Issue [IP] PMID [PMID]
Author [AU] Journal [TA] Publisher [PUBN]
Author Identifier [AUID] Language [LA] Publication Date [DP]
Book [book] Last Author [LASTAU] Publication Type [PT]
Comment Corrections Location ID [LID] Secondary Source ID [SI]
Corporate Author [CN] MeSH Date [MHDA] Subset [SB]
Create Date [CRDT] MeSH Major Topic [MAJR] Supplementary Concept[NM]
Completion Date [DCOM] MeSH Subheadings [SH] Text Words [TW]
EC/RN Number [RN] MeSH Terms [MH] Title [TI]
Editor [ED] Modification Date [LR] Title/Abstract [TIAB]
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Entrez Date [EDAT] NLM Unique ID [JID] Transliterated Title [TT]

Filter [FILTER] Other Term [OT] UID [PMID]
First Author Name [1AU] Owner Version
Full Author Name [FAU] Pagination [PG] Volume [VI]
Full Investigator Name [FIR] Personal Name as Subject [PS]
Grant Number [GR]

Affiliation [AD]
If available, affiliation includes the institution name and address (including e-mail address) of
the first author of the article as it appears in the journal, e.g., cleveland [ad] AND clinic [ad].

Article Identifier [AID]

Includes article identifiers submitted by journal publishers such as doi (digital object identifier).
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These data are typically used for generating LinkOut links.

All Fields [ALL]

Untagged terms and terms tagged with [all fields] are processed using Automatic Term
Mapping. Terms that do not map are searched in all search fields except for Place of Publication
and Transliterated Title. Terms enclosed in double quotes or truncated will be searched in all
fields and not processed using automatic term mapping. PubMed ignores stopwords.

Author [AU]
The format to search for this field is: last name followed by a space and up to the first two
initials followed by a space and a suffix abbreviation, if applicable, all without periods or a
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comma after the last name (e.g., fauci as or o'brien jc jr). Initials and suffixes may be omitted
when searching.

PubMed automatically truncates a search for an author's name to account for varying initials,
e.g., o'brien j [au] will retrieve o'brien ja, o'brien jb, o'brien jc jr, as well as o'brien j. To turn
off this automatic truncation, enclose the author's name in double quotes and tag with [au] in
brackets, e.g., "o'brien j" [au] to retrieve just o'brien j.

Searching by full author name for articles published from 2002 forward is also possible, if
available. Full names display in the FAU field on the MEDLINE display format. Various limits

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on the number of authors included in the MEDLINE citation have existed over the years (see
NLM policy on author names).

Author Identifier [auid]

The author identifier includes a unique identifier associated with an author, corporate or
investigator name, if supplied by a publisher. The field includes the the orginaization authority
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that established the unique identifier, e.g., ORCID, ISNI, VIAF.

Book [book]
The book search field includes book citations, e.g., genereviews [book].

Use the following untagged searches to retrieve all book or book chapters, e.g., ataxia AND
pmcbookchapter

books and chapters: pmcbook

books: pmcbooktitle
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book chapters: pmcbookchapter

Comment Correction Type

The data in these fields are citations to other associated journal publications, e.g., comments
or errata. Often these link to the respective citation. Comments/Corrections data can be
retrieved by the search term that follows each type:
• Comment in: hascommentin
• Comment on: hascommenton
• Erratum in: haserratumin
• Erratum for:: haserratumfor
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• Corrected and republished in: hascorrectedrepublishedin

• Corrected and republished from: hascorrectedrepublishedfrom
• Partial Retraction in: haspartialretractionin
• Partial Retraction of: haspartialretractionof
• Republished in: hasrepublishedin
• Republished from: hasrepublishedfrom
• Retraction in: hasretractionin
• Retraction of: hasretractionof
• Update in: hasupdatein
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• Update of: hasupdateof

• Summary for patients in: hassummaryforpatientsin
• Original Report in: hasoriginalreportin

Corporate Author [CN]

Corporate author identifies the corporate or collective authorship of an article. Corporate names
display exactly as they appear in the journal.

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Note: Citations indexed pre-2000 and some citations indexed in 2000-2001 retain corporate
authors at the end of the title field. For comprehensive searches, consider including terms and/
or words searched in the title field [ti].

Create Date [CRDT]

The date the citation record was first created.
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Completion Date [DCOM]

The date NLM completed processing the citation.

Editor [ED]
The editor search field include the editors for book or chapter citations.

EC/RN Number [RN]

Number assigned by the Enzyme Commission (EC) to designate a particular enzyme or by the
Chemical Abstracts Service (CAS) for Registry Numbers, e.g., 1-5-20-4[rn]
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Entrez Date [EDAT]

Date the citation was added to the PubMed database. Exceptions: As of December 15, 2008,
citations added to PubMed more than twelve months after the date of publication have the
EDAT set to the date of publication, except for book citations. Prior to this, the Entrez Date
was set to the Publication Date on citations published before September 1997.

Search results are displayed in Entrez Date order, i.e., last in, first out.

To search for a date range, insert a colon (:) between each date (e.g., 1996:1997 [edat] or
1998/01:1998/04 [edat]).

Note: The Entrez Date is not changed to reflect the date a publisher supplied record is elevated
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to in process or when an in process record is elevated to indexed for MEDLINE.

See Searching By Date for additional information.

Filter [FILTER] [SB]

Technical tags used by LinkOut, filters include:
• loall[sb] - citations with LinkOut links in PubMed
• free full text[sb] - citations that include a link to a free full-text article
• full text[sb] - citations that include a link to a full-text article

First Author Name [1AU]

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The first personal author name in a citation.

Full Author Name [FAU]

The full author name for articles published from 2002 forward, if available. Full author searches
can be entered in natural or inverted order, e.g., julia s wong or wong julia s.

Full Investigator or Collaborator Name [FIR]

The full investigator or collaborator name for articles, if available. Full investigator searching
can be searched in natural or inverted order, e.g., harry janes or janes harry.

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Grant Number [GR]

The grant number search field includes research grant numbers, contract numbers, or both that
designate financial support by agencies of the US PHS (Public Health Service), and other
national or international funding sources. The four parts of the grant data are:
1 number, e.g., LM05545
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2 PHS 2-character grant abbreviation, e.g., LM

3 institute acronym, e.g., NLM NIH HHS
4 country, e.g., United States
Each individual grant part can be searched using [gr], e.g., NIH[gr]

See Grant codes and agency abbreviations used in grant numbers for the 2-character
abbreviations, PHS agency acronyms, and other US and non-US funding organization.

More information about grant numbers:

• NIH grant numbers, e.g., 5R01CA101211-03, typically have three main parts:
– A prefix that indicates the type of grant, e.g., 5R01
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– An 8-character serial number consisting of a 2-character grant abbreviation

and a 6-digit number, e.g., CA101211
– A suffix with additional data such as grant year, e.g, 03
• To search for an individual NIH grant number use the 8-character serial number and
[gr] tag, e.g., ca101211[gr].
• Grant numbers display in PubMed as they appear in the published article. If the grant
number in the journal article is not 6 digits, e.g., CA84141, search by inserting a leading
zero, e.g., ca084141[gr], so the entire string is a total of 8 characters long.
• For a broader search, use the PHS 2-character grant abbreviation, e.g., ca[gr] or the
institute acronym, e.g., nci[gr].
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• Search non-PHS organization names in full or individual parts, e.g., wellcome trust
[gr], wellcome[gr].
• For generic numbers, it may be necessary to include the organization or country, e.g.,
193588[gr] AND canada[gr].

ISBN [ISBN]
The ISBN for book or book chapters.

Issue [IP]
The number of the journal issue in which the article was published.
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Investigator [IR]
Names of principal investigator(s) or collaborators who contributed to the research. Search
names following the author field format, e.g., soller b [ir]

Journal [TA]
The journal search field includes the journal title abbreviation, full journal title, or ISSN number
(e.g., J Biol Chem, Journal of Biological Chemistry, 0021-9258). If a journal title contains
special characters, e.g., parentheses, brackets, enter the name without these characters, e.g.,
enter J Hand Surg [Am] as J Hand Surg Am.

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Language [LA]
The language search field includes the language in which the article was published. Note that
many non-English articles have English language abstracts. You may search using either the
language or the first three characters of most languages, e.g., chi [la] retrieves the same results
as chinese [la]. The most notable exception is jpn [la] for Japanese.
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Last Author Name [LASTAU]

The last personal author name in a citation.

Location ID [LID]
Location ID includes the DOI or publisher ID that serves the role of pagination to locate an
online article.

MeSH Date [MHDA]

The date the citation was indexed with MeSH Terms and elevated to MEDLINE for citations
with an Entrez Date after March 4, 2000. The MeSH Date is initially set to the Entrez Date
when the citation is added to PubMed. If the MeSH Date and Entrez Date on a citation are the
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same, and the Entrez Date is after March 4, 2000, the citation has not yet been indexed.

Dates must be entered using the format YYYY/MM/DD [mhda], e.g. 2000/03/15 [mhda]. The
month and day are optional (e.g., 2000 [mhda] or 2000/03 [mhda]).

To enter a date range, insert a colon (:) between each date (e.g., 1999:2000 [mhda] or
2000/03:2000/04 [mhda]).

MeSH Major Topic [MAJR]

A MeSH term that is one of the main topics discussed in the article denoted by an asterisk on
the MeSH term or MeSH/Subheading combination, e.g., Cytokines/physiology* See MeSH
Terms [MH] below.
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MeSH Subheadings [SH]

MeSH Subheadings are used with MeSH terms to help describe more completely a particular
aspect of a subject. For example, the drug therapy of asthma is displayed as asthma/drug
therapy; see MeSH/Subheading Combinations in MeSH Terms [MH] below.

The MeSH Subheading field allows users to "free float" Subheadings, e.g., hypertension [mh]
AND toxicity [sh].

MeSH Subheadings automatically include the more specific Subheading terms under the term
in a search. To turn off this automatic feature, use the search syntax [sh:noexp], e.g., therapy
[sh:noexp].
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In addition, you can enter the two-letter MeSH Subheading abbreviations rather than spelling
out the Subheading, e.g., dh [sh] = diet therapy [sh].

MeSH Terms [MH]

The NLM Medical Subject Headings controlled vocabulary of biomedical terms that is used
to describe the subject of each journal article in MEDLINE. MeSH contains approximately 26
thousand terms and is updated annually to reflect changes in medicine and medical
terminology. MeSH terms are arranged hierarchically by subject categories with more specific

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terms arranged beneath broader terms. PubMed allows you to view this hierarchy and select
terms for searching in the MeSH Database.

Skilled subject analysts examine journal articles and assign to each the most specific MeSH
terms applicable - typically ten to twelve. Applying the MeSH vocabulary ensures that articles
are uniformly indexed by subject, whatever the author's words.
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Notes on MeSH Terms and Major MeSH Topic search fields:

• To search the term only as a MeSH term, it must be tagged using the search field, e.g.,
[mh] for MeSH Terms or [majr] for MeSH Major Topic. A tagged term is checked
against the MeSH translation table, and then mapped to the appropriate MeSH term
(s). To turn off mapping to multiple MeSH terms, enter the tagged MeSH term in
double quotes.
• MeSH terms are arranged hierarchically by subject categories with more specific terms
arranged beneath broader terms. MeSH terms in PubMed automatically include the
more specific MeSH terms in a search. To turn off this automatic feature, use the search
syntax [mh:noexp], e.g., neoplasms [mh:noexp].For more detailed information about
MeSH vocabulary including the hierarchical structure, please see the MeSH
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homepage.
• MeSH/Subheading Combinations: To directly attach MeSH Subheadings, use the
format MeSH Term/Subheading, e.g., neoplasms/diet therapy. You may also use the
two-letter MeSH Subheading abbreviations, e.g., neoplasms/dh. The [mh] tag is not
required, however [majr] may be used, e.g., plants/genetics[majr]. Only one
Subheading may be directly attached to a MeSH term. For a MeSH/Subheading
combination, PubMed always includes the more specific terms arranged beneath
broader terms for the MeSH term and also includes the more specific terms arranged
beneath broader Subheadings. The broader Subheading, or one of its indentions’, will
be directly attached to the MeSH term or one of its indentions’. For example,
hypertension/therapy also retrieves hypertension/diet therapy; hypertension/drug
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therapy; hypertension, malignant/therapy; hypertension, malignant/drug therapy, and

so on, as well as hypertension/therapy.
• To turn off the automatic inclusion of the more specific terms, use the syntax
[field:noexp], e.g., hypertension [mh:noexp], or hypertension [majr:noexp], or
hypertension/therapy [mh:noexp]. The latter example turns off the more specific terms
in both parts, searching for only the one Subheading therapy attached directly to only
the one MeSH term hypertension.
• If parentheses are embedded in a MeSH term, replace the parentheses with a space and
tag with [mh] e.g., enter the MeSH term Benzo(a)pyrene as benzo a pyrene [mh].
• MeSH terms can be selected for searching in the MeSH database and from the advanced
search builder index.
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Modification Date [LR]

Modification date is a completed citation’s most recent revision date.
NLM Unique ID [JID]
The NLM ID is the alpha-numeric identifier for the cited journal that was assigned by the NLM
Integrated Library System LocatorPlus, e.g., 0375267 [jid].

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Other Term [OT]

Mostly non-MeSH subject terms (keywords). The other term data may be marked with an
asterisk to indicate a major concept, however asterisks are for display only. You cannot search
other terms with a major concept tag. The OT field is searchable with the text word [tw] and
other term [ot] search tags.
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Owner
The owner search field includes the acronym that identifies the organization that supplied the
citation data. Search using owner + the owner acronym, e.g. ownernasa.

Pagination [PG]
Enter only the first page number that the article appears on. The citation will display the full
pagination of the article but this field is searchable using only the first page number.

Personal Name as Subject [PS]

Use this search field tag to limit retrieval to where the name is the subject of the article, e.g.,
varmus h[ps]. Search for personal names as subject using the author field format, e.g., varmus
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h[ps].

Pharmacological Action [PA]

Substances known to have a particular pharmacologic action. Each pharmacologic action term
index is created with the drug/substance terms known to have that effect. This includes both
MeSH terms and terms for Supplementary Concept Records.

Place of Publication [PL]

Indicates the cited journal's country of publication. Geographic place of publication regions
are not searchable. In order to retrieve records for all countries in a region (e.g., North America)
it is necessary to OR together the countries of interest. Note: This field is not included in all
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fields or text word retrieval.

PMCID & MID

Search for PMC or manuscript identifiers using the appropriate prefix followed by the ID
number, e.g., PMC2600426.

PMID [PMID]
To search for a PubMed Identifier (PMID), enter the ID with or without the search field tag
[pmid]. You can search for several PMIDs by entering each number in the search box separated
by a space (e.g., 17170002 16381840); PubMed will or the PMIDs together.
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To search in combination with other terms, you must enter the search field tag, e.g., lipman
[au] 16381840[pmid].

PMIDs do not change over time or during processing and are never reused.

Publication Date [DP]

Publication date is the date that the article was published.

Dates or date ranges must be searched using the format yyyy/mm/dd [dp], e.g. 1998/03/06 [dp].
The month and day are optional (e.g., 1998 [dp] or 1998/03 [dp]).

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To enter a date range search, insert a colon (:) between each date (e.g., 1996:1998 [dp] or
1998/01:1998/04 [dp]).

Use the following format to search X days, months or years immediately preceding today’s
date where X = numeric value:
• “last X days”[dp]
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• “last X months”[dp]
• “last X year”[dp]
Note:
• Journals vary in the way the publication date appears on an issue. Some journals include
just the year, whereas others include the year plus month or year plus month plus day.
And, some journals use the year and season (e.g., Winter 1997). The publication date
in the citation is recorded as it appears in the journal.
• If an article is published electronically and in print on different dates both dates are
searchable and may be included on the citation prefaced with an Epub or Print label.
The electronic date will not be searchable if it is later than the print date, except when
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range searching.
• To search for electronic dates only use the search tag [EPDAT], for print dates only
tag with [PPDAT].

Publication Type [PT]

Describes the type of material the article represents (e.g., Review, Clinical Trial, Retracted
Publication, Letter); see the PubMed Publication Types, e.g., review[pt]. Publication Types
are arranged hierarchically with more specific terms arranged beneath broader terms.
Publication types automatically include the more specific publication types in a search. To turn
off this automatic feature, use the search syntax [pt:noexp], e.g., review [pt:noexp].
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Publisher [PUBN]
Includes publisher names for Bookshelf citations.

Secondary Source ID [SI]

The SI field identifies secondary source databanks and accession numbers, e.g., GenBank,
GEO, PubChem, ClinicalTrials.gov, ISRCTN. The field is composed of the source followed
by a slash followed by an accession number and can be searched with one or both components,
e.g., genbank [si], AF001892 [si], genbank/AF001892 [si].

The SI field and the NCBI sequence database links are not linked. The PubMed links to these
databases are created from the reference field of the GenBank or GenPept flat file. These
references include citations that discuss the specific sequence presented in these flat files.
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Subset [SB]
The subset field is a method of restricting retrieval by subject, citation status and journal
category, with the search tag [SB]. See also filters and Finding Related Links for a Citation
Using LinkOut.

Supplementary Concept [NM]

Includes chemical, protocol or disease terms. Synonyms to the supplementary concepts will
automatically map when tagged with [nm]. This field was implemented in mid-1980; however,
many chemical names are searchable as MeSH terms before that date.

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Text Words [TW]

Includes all words and numbers in the title, abstract, other abstract, MeSH terms, MeSH
Subheadings, Publication Types, Substance Names, Personal Name as Subject, Corporate
Author, Secondary Source, Comment/Correction Notes, and Other Terms (see Other Term
[OT] above) typically non-MeSH subject terms (keywords), including NASA Space Flight
Mission, assigned by an organization other than NLM.
PubMed Help

Title [TI]
Words and numbers included in the title of a citation, as well as the collection title for book
citations.

Title/Abstract [TIAB]
Words and numbers included in the title, collection title, abstract, and other abstract of a
citation. English language abstracts are taken directly from the published article. If an article
does not have a published abstract, NLM does not create one.

Transliterated Title [TT]

PubMed Help

Words and numbers in title originally published in a non-English language, in that language.
Non-Roman alphabet language titles are transliterated. Transliterated title is not included in
All Fields or Text Word retrieval so you must search terms using the [tt] search tag.

Version
The PMID of a versioned citation is persistent. To retrieve previous versions use the format
PMID.version, e.g., 20029666.4. The abstract display includes an “Other versions” link that
lists the previous versions and corresponding publication date. Only the most recent version
of a citation will be indexed, therefore the content, e.g., author names, abstract terms, from
previous versions will not be retrieved for PubMed searches. Search ispreviousversion to
retrieve all previous versions of citations.
PubMed Help

Volume [VI]
The number of the journal volume in which an article is published.

Searching PubMed
Section Contents
• A basic search and automatic term mapping

• Searching by author

• Searching by journal title

PubMed Help

• Searching by date
• Previewing the number of search results
• Filtering searches
• Combining searches using History
• Browsing the index of terms
• Searching for a phrase
• Truncating search terms

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• Combining search terms with Boolean operators (AND, OR, NOT)

• Searching in a specific field or index
• Finding a citation using the Single Citation Matcher
• Finding citations related to a citation
•
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Using Clinical Queries

• Finding systematic reviews

A basic search

1 Identify the key concepts for your search.

Example

Find citations about bronchodilators for treating asthma in children.

The key concepts are bronchodilators, asthma and children

PubMed Help

1 Enter terms into the search box.

2 Press the Enter key or click Search.
A spell checking feature suggests alternative spellings for search terms that may include
misspellings.

A citation sensor displays results for searches that include terms characteristic of citation
searching, e.g., author names, journal titles, publication dates, and article titles.

A gene sensor checks queries, and if it detects the symbol for a gene, links to the Gene
database.

Recent Activity displays your recent database searches and document views.
PubMed Help

Additional sensors and discovery ads related to your search may display with your results.

Searching by author

Enter the author’s name in the format of last name followed by initials. Omit punctuation.

Examples

smith ja
PubMed Help

jones k

More information about author searching:

• Click Advanced and use the builder. Select Author from the All Fields menu and enter
an author’s name. The author search box includes an autocomplete feature.
• Author names are automatically truncated to account for varying initials and
designations such as Jr. To turn off the truncation, use double quotes around the author's
name with the author search field tag [au], e.g., "smith j" [au].
• If only the author's last name is entered, tag the name with the author search field [au],
to find the name in the author field only.

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• Use the [1au] tag to search for the first personal author or [lastau] to search for the last
personal author name in a citation.
• You may click an author link on the abstract display to execute a search for the author
in PubMed. Results will display using a ranking algorithm if the author name is
computationally similar for additional PubMed citations.
PubMed Help

Example

woods [au]

Full author names may be searched for citations published from 2002 forward if the full author
name is available in the article. Enter a full author name in natural or inverted order, e.g., julia
s wong or wong julia s.

Example

Joshua Lederberg

Garcia Algar, Oscar

PubMed Help

More information about full author searching:

• A comma following the last name for searching is optional. For some names, however,
it is necessary to distinguish which name is the last name by using the comma following
the last name, e.g., james, ryan.
• Omit periods after initials and put all suffixes at the end, e.g., vollmer charles jr
• Initials and suffixes are not required, if you include a middle initial or suffix, you will
only retrieve citations for articles that were published using the middle initial or suffix.
• To distinguish author initials that may match a full author name use the [fau] search
tag, e.g., peterson do[fau].
PubMed Help

Searching by journal title

Enter in the search box one of the following:

• full journal title (e.g., molecular biology of the cell)
• title abbreviation (e.g., mol biol cell)
• ISSN number, a standardized international code (e.g., 1059-1524)
Example

new england journal of medicine

PubMed Help

To find full journal names, use the NLM Catalog, or mouseover the citation journal
abbreviation.
1 Click Journals in NCBI Databases on the PubMed homepage.
2 Enter the journal name and click Search.
More information about journal searching:
• Click Advanced and use the Builder. Select Journal from the All Fields menu and
enter a journal title. The journal search box includes an autocomplete feature.
• Tag the journal title by using the search field [ta] to limit your search to only the journal,
e.g., gene therapy[ta], scanning [ta].

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• Searching with the full journal title or abbreviation is recommended for complete
retrieval of indexed items; older citations may not have an ISSN.
• If a journal title or abbreviation includes a special character (e.g., parentheses, brackets,
&), enter the title or abbreviation without the special characters. For example, to search
by the journal abbreviation j hand surg [am], enter j hand surg am.
PubMed Help

• Searching for a journal will automatically map to the official journal title and the title
associated with an alternative title, if one exists. To turn off this automatic mapping
enter the journal in double quotes and tag with [ta], e.g., “science”[ta].
A list of journals included in PubMed is available by FTP.

Searching by date
1 Click Advanced and use the Builder.
2 Select a date field from the All Fields menu, e.g., Date – Publication, and enter a single
date or a date range in the fill-in-the-blank boxes. Month and day are optional. If you
want to search for a date range up to the current date, do not edit the to ‘present’ date
box.
PubMed Help

3 Click Search.

Searching by a single date in the search box

Enter dates using the format yyyy/mm/dd [date field]. There is a selection of date fields to use:
• Date of Publication [dp] - Date searching includes both print and electronic dates of
publication. Searching for a single date does not include items when the electronic date
of publication is after the print date.
• Electronic Date of Publication (if applicable) [epdat]
• Print Date of Publication (if applicable) [ppdat]
• Entrez Date [edat] - The date the citation first entered PubMed.
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• MeSH Date [mhda] - The date the citation was indexed with MeSH terms.
• Create Date [crdt] – The date the citation record was first created.
The month and day are optional.

Example

1997/10/06 [edat]

1998/03/15 [dp]

1997 [edat]

1997/03 [dp]
PubMed Help

Searching for a date range in the search box

Enter date ranges using a colon (:) between each date followed by a [date field].

Example

1993:1995 [dp]

1997/01:1997/06 [edat]

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2002:2009[crdt]

Comprehensive searches for a full year should be entered as 2000:2000[dp] rather than 2000
[dp] to retrieve citations with a different print and electronic year of publication.
PubMed Help

Date range searching includes both print and electronic dates of publication.

Searching for a relative date range

Use the following format to search for a relative date range:
• term="last X days"[Search Tag]
• term="last X months"[Search Tag]
• term="last X years"[Search Tag]
where X is the number of days, months or years immediately preceding today’s date and
[Search Tag] is the date search tag: [dp], [edat] or [crdt].
PubMed Help

Filters
Tutorial

You can narrow your search results by article types, text availability, publication dates,
species, languages, sex, subjects, journal categories, ages and search fields.
1 Run a search in PubMed.
2 To activate a sidebar filter, click the filter selection. A checkmark will appear next to
the activated filters.
3 Subsequent searches will be filtered until the selected filters are cleared.
PubMed Help

Note:
• To add additional filter categories to the sidebar, click the “Show additional filters”
link, select the additional categories, and then click Show. To activate the additional
filters, click the filter selection.
• When filters are selected a Filters activated message will display on the results page.
• To turn off filters, click either the “Clear all” link to remove all the filters, the “clear”
link next to a filter category to clear the selections within that category, or the individual
filter.
• The "in process" and "supplied by publisher" citations may be excluded for some filter
selections because they have not yet completed the MEDLINE indexing process.
• Only valid filter options for a result set will display as a sidebar selection.
PubMed Help

• Users can also activate additional filters with My NCBI filters.

Article types
Select article types to narrow your results based on the type of material the article represents,
such as: Clinical Trial and Review.

Click the “more …” link, to add additional article types, and then click Show. The complete
list of MEDLINE publication types is available. Systematic review articles are produced using
a search strategy.

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These filters may exclude "in process" and "supplied by publisher" citations because they have
not yet completed the MEDLINE indexing process.

Text availability
To filter your results to only citations that include a link to full text, a link to free full text, or
an abstract, click the appropriate selections.
PubMed Help

Alternatively, you may search for citations with links to full text, free full text or include an
abstract using the values: full text[sb], free full text[sb], or 'hasabstract'. No search field tag is
required for hasabstract. You may also search for all MEDLINE citations with a structured
abstract with ‘hasstructuredabstract’.

Example

neoplasms AND hasabstract

Note: Most citations in PubMed to articles published before 1975 do not include abstracts.
PubMed Help

Publication Dates
From the filter sidebar Publication dates category, click 5 years, 10 years, or enter a date in the
custom range box to filter your results by publication date.

Species
Species selections restrict your results to human or animal studies.

This filter will exclude "in process" and "supplied by publisher" citations because they have
not yet completed the MEDLINE indexing process.

Languages
PubMed Help

To add languages to the sidebar, click the “Show additional filters” link, select Languages, and
then click Show. Language selections restrict your search to articles written in the specific
language.

Click the “more …” link, to add additional languages, and then click Show.

Sex
Sex restricts your search results to a specific sex for a human study.

To add sex to the sidebar, click the “Show additional filters” link, select Sex, and then click
Show.
PubMed Help

This filter will exclude "in process" and "supplied by publisher" citations because they have
not yet completed the MEDLINE indexing process.

Subjects
Subject filters restrict retrieval to specific subjects.

To add subjects to the sidebar, click the “Show additional filters” link, select Subjects, and
then click Show. Subject filters include:
• AIDS
• Bioethics

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• Cancer
• Complementary Medicine
• Dietary Supplements
• History of Medicine
•
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Systematic Reviews
• Toxicology
• Veterinary Science
Subjects use a specialized search strategy.

Subjects can also be searched using the respective search value of aids, bioethics, cancer,
cam, dietsupp, history, space, systematic, tox or veterinary followed by the [sb] search tag.
The Systematic reviews selection is included in the article types' category.

Example
PubMed Help

asthma AND cam [sb]

Journal categories & more subsets

To add journal categories to the sidebar, click the “Show additional filters” link, select Journal
categories, and then click Show.

The Journal/Citation subsets restrict retrieval to specialized journals or articles on specialized

topics in other journals. The table lists the journal subsets, along with the code used for
searching. Some subsets are closed and are no longer being assigned to current data.

To search for a Journal/Citation subset, enter in the search box: jsubset?, where ? represents
the subset code.
PubMed Help

Example

neoplasms AND jsubsete

This search will filter your retrieval to citations from bioethics journals or selected bioethics citations from other journals.

The Journal/Citation subset does not require a search tag.

PubMed Central Subset

To restrict retrieval to citations that have a free full-text article available in PubMed Central
(PMC), search pubmed pmc[sb].
PubMed Help

Example

protein p53 AND pubmed pmc[sb]

Use the PMID : PMCID Converter to identify one type of ID with the other.

Citation Status Subsets

The citation status indicates the processing stage of an article in the PubMed database (see
PubMed Citation Status Subsets).

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The status tags are displayed with each citation in the search results. To search for a particular
citation status, enter one of the search terms below followed by the [sb] search tag
• publisher
• inprocess
• medline
PubMed Help

• oldmedline
• pubmednotmedline
Example

n engl j med AND medline [sb]

To search for the total number of PubMed citations, enter all [sb] in the search box.

Ahead of Print Citations

Publishers may submit citations for articles that appear on the web prior to their publication in
final or print format. To search for these ahead-of-print citations, enter pubstatusaheadofprint.
PubMed Help

Example

pubstatusaheadofprint AND gene

Following publication of the completed issue, the date an article was published electronically
is also displayed, e.g. Proc Natl Acad Sci U S A. 2003 Apr 1;100(7):3925-9. Epub 2003 Mar
24.

Ages
Age filters restrict results to a specific age group for a human study.
PubMed Help

To add ages to the sidebar, click the “Show additional filters” link, select Ages, and then click
Show.

Age filters include:

• 80 and over: 80+ years
• Adolescent: 13-18 years
• Adult: 19+ years
• Adult: 19-44 years
• Aged: 65+ years
• Child: 0-18 years
PubMed Help

• Child: 6-12 years

• Infant: 1-23 months
• Infant: birth-23 months
• Middle Aged + Aged: 45+ years
• Middle Aged: 45-64 years
• Newborn: birth-1 month
• Preschool Child: 2-5 years
• Young Adult: 19-24 years

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These filters will exclude "in process" and "supplied by publisher" citations because they have
not yet completed the MEDLINE indexing process.

Search Fields
Choose a search field to limit all terms entered in the search box to the selected field.
PubMed Help

Click the “Show additional filters” link, select Search fields, and then click Show. Click the
Choose... link under Search fields, select a search field, and then click Apply.

Advanced Search
Tutorial

• Searching by a specific field

• Browsing the index of terms
• Combining searches using history
• Previewing the number of search results
PubMed Help

Searching by a specific field

Use the Advanced search Builder to search for terms in a specific search field.
• To search by author, select Author from the All Fields menu, and then enter an author’s
name, the name will automatically display in the search box. The author search box
includes an autocomplete feature.
• To search by journal, select Journal from the All Fields menu, enter a journal name;
the journal search box also includes an autocomplete feature.
• To search for other fields in a citation, use the pull-down menus to select a field before
entering a term in the search builder box.
• Terms entered in the builder are automatically added to the search box.
PubMed Help

• Note that the default Boolean operator is AND; if desired, choose OR or NOT from
the pull-down menu.
You may also search a specific field, and bypass the automatic term mapping, by adding a
search tag to a term (Search Field Descriptions and Tags).
• The search tag must be enclosed in square brackets.
• Case and spacing do not matter (e.g., crabs [mh] = Crabs[mh]).
Example

aromatherapy [mh]
PubMed Help

Browsing the index of terms

The Advanced search builder Show index list provides an alphabetical display of all terms in
each PubMed search field. You can browse by all fields or within a specific field such as MeSH
Subheadings..
1 Click Advanced and use the Builder to select a search field from the All Fields menu.
2 Enter a term in the search box, and then click Show index list.
3 The index displays an alphabetic list of search terms and the number of citations for
each term. Click Previous or Next to move within the index.
4 Scroll until you find a term and then highlight it to add it to the search box.

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More information about using the index:

PubMed processes all Boolean operators left to right. The builder will automatically OR (and
add parentheses) for multiple terms selected from the index.

Previewing the number of search results

PubMed Help

Use the Add to history link in advanced search to display the items found before displaying
the search results:
1 Click Advanced.
2 Use the builder to add search terms to the search box.
3 Click Add to history to display the number of results in history.
4 To display the citations, click the history Items found link.

Combining searches using History

Searches can be combined or used in subsequent searches using the search number from
Advanced search History.
PubMed Help

1 Click Advanced.
2 In History, click Add to move the search to the Builder.
3 Alternatively, click the search number to display additional options to add the search
to the Builder, including Boolean operators OR or NOT. Other menu options include:
• Delete from history
• Show search results
• Show search details
• Save in My NCBI
4 Add additional search terms in the builder.
PubMed Help

5 Click Search.
Examples

#2 AND #6

#3 AND (drug therapy OR diet therapy)

#5 gene therapy

More information about the History:

• The history will be lost after 8 hours of inactivity.
• Click Clear history to delete all searches from history.
• Click “Download history” to generate a CSV file. Please note that Microsoft Excel is
PubMed Help

typically unable to display or print more than a maximum of 1024 characters in a cell;
therefore, you may want to open the CSV file with a text editor to display your complete
searches.
• PubMed will move a search statement number to the top of the History if a new search
is the same as a previous search.
• History search numbers may not be continuous because some numbers are assigned
to intermediate processes, such as displaying a citation in another format.

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• The maximum number of searches available in History is 100. Once the maximum
number is reached, PubMed will remove the oldest search from history and add the
most current search.
• A separate history will be retained for each database, although the search numbers will
be assigned sequentially for all databases.
PubMed Help

• The history feature requires your web browser to be set to accept cookies.
• Citations in the Clipboard are represented by the search number #0, which may be used
in searches. For example, to limit the citations you have collected in the clipboard to
English language citations, use the following search: #0 AND english [la]. This does
not change or replace the Clipboard contents.

Searching for a phrase

PubMed does not perform adjacency searching. However, many phrases are recognized by the
MeSH Translation Table used in PubMed's Automatic Term Mapping (ATM). For example,
if you enter fever of unknown origin, PubMed recognizes this phrase as a MeSH Term. If a
phrase is not recognized you can bypass ATM and search for a phrase using the following
formats:
PubMed Help

Examples

• Enclose the phrase in double quotes: “kidney allograft”

• Use a search tag: kidney allograft[tw]
• Use a hyphen: first-line
• Truncate: kidney allograft*

More information for phrase searching:

• If you use a hyphen or quotes and the phrase is not found, the hyphen or quotes are
ignored and the phrase is processed using automatic term mapping. Phrases may appear
PubMed Help

in a PubMed record but not be in the phrase index.

• When you enter your search terms as a phrase PubMed will not perform automatic
term mapping that includes the MeSH term and any specific terms indented under that
term in the MeSH hierarchy. For example, "health planning" will include citations that
are indexed to the MeSH term, Health Planning, but will not include the more specific
terms, e.g., Health Care Rationing, Health Care Reform, Health Plan Implementation,
that are included in the automatic MeSH mapping.
• Truncating a word in a multi-word search may result in an unexpected phrase search.
For example the search, fetus infection* maternal will treat fetus infection* as a phrase.
The results page search details box includes the search translations.
• To browse the indexed phrases, use the Advanced search builder show index list. Select
PubMed Help

a search field, enter the beginning of a phrase, and then click Show index list.

Truncating search terms

To search for all terms that begin with a word, enter the word followed by an asterisk (*), the
wildcard character.

Example

flavor*

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Finds terms that begin with the root term flavor, such as flavored, flavorful, flavoring, etc.

More information about truncation:

• PubMed searches for the first 600 variations of a truncated term. If a truncated term
PubMed Help

(e.g., tox*) produces more than 600 variations, a warning message displays to lengthen
the root word to search for all endings.
• Truncation turns off automatic term mapping and the process that includes the MeSH
term and any specific terms indented under that term in the MeSH hierarchy. For
example, heart attack* will not map to the MeSH term Myocardial Infarction or include
any of the more specific terms, e.g., Myocardial Stunning; Shock, Cardiogenic.
• Truncating a word in a multi-word search may result in an unexpected phrase search.
For example the search, fetus infection* maternal will treat fetus infection* as a phrase.
• Trucation stops at the end of a term, that is, it does not process beyond a space.

Finding a citation using the Single Citation Matcher

PubMed Help

The Single Citation Matcher has a fill-in-the-blank form for searching for a citation when you
have some bibliographic information, e.g., journal name, volume, page number.
1 Click Single Citation Matcher on the PubMed homepage or from the Advanced
search more resources menu.
2 Enter the citation information.
3 Click Go.
More information about using the Single Citation Matcher:
• The journal box includes an autocomplete feature that suggests titles as you enter a
title abbreviation or full title. Titles displayed by the autocomplete menu are in ranked
order based on the number of citations in PubMed.
PubMed Help

• After selecting a journal with special characters (e.g., ampersand, colon) when using
the Back button to return to the Single Citation Matcher you must clear and reenter the
title.
• The author box also includes an autocomplete feature that suggests author names in
ranked order based on the number of citations. Full author names may be searched for
citations published from 2002 forward if the full author name is available in the article.
• Click either the 'Only as first author' or ‘Only as last author’ check box to limit an
author name to the first or last author.

Combining search terms with Boolean operators (AND, OR, NOT)

PubMed applies an AND operator between concepts, e.g., “vitamin c common cold” is
PubMed Help

translated as vitamin c AND common cold. Enter Boolean operators in uppercase characters
to combine or exclude search terms:
• AND retrieves results that include all the search terms.
• OR retrieves results that include at least one of the search terms.
• NOT excludes the retrieval of terms from your search.
Examples

Find citations on DNA that were authored by Dr. Crick in 1993:

dna [mh] AND crick [au] AND 1993 [dp]

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Find citations on the effects of heat or humidity on multiple sclerosis:

(heat OR humidity) AND multiple sclerosis

Find citations about arthritis excluding the Publication Type Letter:

arthritis NOT letter [pt]
PubMed Help

PubMed processes searches in a left-to-right sequence. Use parentheses to “nest” concepts that
should be processed as a unit and then incorporated into the overall search.

Example

common cold AND (vitamin c OR zinc)

More information about using Boolean operators:

Boolean operators must be used when combining tagged search terms as follows: search term
[tag] BOOLEAN OPERATOR search term [tag]. (See Search Field Descriptions and
Tags)
PubMed Help

• In a multi-word search PubMed will use Automatic Term Mapping to identify

concepts. For example, for the search air bladder fistula, PubMed will search "air
bladder" as a phrase. If you do not want this automatic phrase parsing, enter each term
separated by the Boolean operator AND, e.g., air AND bladder AND fistula.
• The search details portlet displays how a search is translated.

Finding citations related to a citation

Consult the Related citations displayed on the abstract format.

The Related citations See all…link will retrieve a pre-calculated set of PubMed citations that
are closely related to the selected article. The related citations will be displayed in ranked order
PubMed Help

from most to least relevant, with the “linked from” citation displayed first.

More information about Related citations:

• The set of related citations is generated by comparing words from the title, abstract,
and MeSH terms using a word-weighted algorithm.
• Select PubMed from the Find Related Data portlet to retrieve related citations for
your result set.
• Filters are not activated for related citation results, however, subsequent searches will
include filters selected prior to displaying related citation results.
• You can refine the list of related citations using Advanced History where the related
citations retrieval is represented as "Related Citations for PubMed (Select PMID)."
PubMed Help

Use this Search number in a search. The related citations retrieval list is displayed in
ranked order from most to least relevant; however, refining the list removes the ranked
order and may remove citations that are most relevant.

Using Clinical Queries

PubMed Clinical Queries provides specialized searches for clinicians:
• Clinical Study Categories - clinical search filters based on the work of Haynes RB
et al.

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• Systematic Reviews - a customized search strategy to retrieve a broad set of citations

that build consensus on biomedical topics and include: systematic reviews, meta-
analyses, reviews of clinical trials, evidence-based medicine, consensus development
conferences, guidelines, and citations from journals specializing in clinical review
studies.
• Medical Genetics - search filters developed in conjunction with the staff of
PubMed Help

GeneReviews: Genetic Disease Online Reviews at GeneTests, University of

Washington, Seattle.

Search by clinical study category

Clinical Study Categories use a specialized search method with built-in search filters that limit
retrieval to citations to articles reporting research conducted with specific methodologies,
including those that report applied clinical research.

To find citations using the Clinical Study Category:

1 Click Clinical Queries from the PubMed homepage or from the advanced search
more resources menu.
PubMed Help

2 Enter your search terms in the search box

3 Select a Category: Therapy, Diagnosis, Etiology, Prognosis, or Clinical prediction
guides
4 Select a Scope: Narrow (specific search) or Broad (sensitive search)
5 Click Search
Example

Find research on diagnosing cystic fibrosis.

On the Clinical Queries page

Enter cystic fibrosis in the search box.

PubMed Help

Choose “diagnosis” under Category and “narrow” under Scope, click Search.

Finding systematic reviews

In PubMed, Systematic Reviews cover a broad set of articles that build consensus on
biomedical topics. A list of related sources on this topic is available.

To search for systematic reviews:

1 Click Clinical Queries from the PubMed homepage or from the advanced search
more resources menu
2 Enter your search terms in the search box
PubMed Help

3 Click Search
Example

Find Systematic Reviews on inhalation therapy for pneumonia.

Go to the Clinical Queries page

Enter the search terms inhalation therapy pneumonia into the search box, click Search.

Alternatively, enter search terms followed by AND systematic[sb] in the search box. For
example, lyme disease AND systematic[sb].

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Medical genetics searches

In PubMed, medical genetics finds citations related to various topics in medical genetics.
1 Click Clinical Queries from the PubMed homepage or from the advanced search
more resources menu
2 Enter search terms in the search box
PubMed Help

3 Choose a specific topic, if applicable

4 Click Search.
Example

Find information on genetic counseling for sickle cell anemia.

Go to the Clinical Queries page

Enter the search terms sickle cell anemia into the search box.

Under Medical Genetics choose Genetic Counseling, click Search.

Understanding Your Search Results

PubMed Help

Search results initially display in a summary format in the order they were entered in PubMed
as last in, first out. You can change the display format.

A default of 20 citations is displayed per page. If there are more than 20 citations, they will be
displayed on subsequent pages.

To display the abstract for a journal article, click the title for each citation. Citations that don’t
include an abstract display the notation “No abstract available.”

PubMed may also include non-English abstracts, if supplied by the publisher. The additional
language view links are available on the Abstract display. The abstract text defaults to English
when a citation has an accompanying non-English abstract.
PubMed Help

Anatomy of Summary Results

PubMed Help

For additional information see: Displaying and Sorting Your Search Results

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Displaying and Sorting Your Search Results

Section Contents

Use Display Settings for:

• Changing the citation format
PubMed Help

• Changing the number of items per page

• Sorting your search results
Use Send to for:
• Saving citations in a File
• Saving citations temporarily in your Clipboard
• Saving citations permanently in My NCBI Collections
• E-mailing citations
• Ordering journal articles
• Printing search results
PubMed Help

Use the results page controls to:

• Move to another page

Changing the citation display format

Results are initially displayed in the Summary format, except a single citation result will display
the abstract format. You can change the display for all or selected citations by selecting a format
from Display Settings.

To change the display format only for selected citations, click the check box to the left of each
citation before selecting a display format.
PubMed Help

See PubMed Citation Display Formats for a description of all the formats.

Changing the number of citations shown per page

From Display Settings, select the number of items per page to display. You can change the
number of citations displayed on a single page from 5 to 200 items.

Sorting your search results

From Display Settings, select a sort by option. Sort options include: Recently Added,
Publication Date, First Author, Last Author, Journal, and Title.

More information about sorting:

•
PubMed Help

Citations in PubMed are displayed in reverse date added order: last in, first out. The
recently added date is the date a record was initially added to PubMed, not the
publication date. The secondary sort is PMID.
• Publication Date sorts the most recent citations first, the secondary sort is journal.
• Publication dates without a month are set to January, multiple months (e.g., Oct-Dec)
are set to the first month, and dates without a day are set to the first day of the month.
Dates with a season are set as: winter = January, spring = April, summer = July and
fall = October.
• First author, last author and journal sort A to Z; the secondary sort is publication date.
First author sorting incorporates all author names in a citation.

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 Page 31

• Results for related data, e.g., related citations, display in ranked order and display the
sort by option: Sorted by Link Ranking.
• You may click an author link on the abstract display to execute a search for the author
in PubMed. If an author name is computationally similar with an author name for
additional PubMed citations, the results will display those citations first, in ranked
order, followed by the non-similar citations. The results sort notation will display as,
PubMed Help

“Sorted by Computed Author.”

Printing Search Results

Use the print function of your web browser.

To print citations from different searches, save the citations in PubMed’s Clipboard, and then
print.

See also:
• Changing the number of citations shown per page
• Changing the citation display format
PubMed Help

Move to another page of search results

The results display the number of citations retrieved and the number of pages necessary to
display all the results. Use Display Settings to change the number of citations shown per page.

Click Next or Prev to move back or forward to adjacent pages and Last or First to display the
first and last page of your results.

Finding Related Resources for a Citation

Section Contents
• Discovering related data in NCBI databases
PubMed Help

• Finding related resources using LinkOut

• Displaying References for a PubMed Central article
• Finding PubMed Central articles that have cited an article
• Finding Bookshelf books that have cited an article
• Reporting broken or problem links

Discovering related data in NCBI databases

Related NCBI databases for summary results are available from the Find Related Data portlet.
Select a database, and then choose a database. PubMed typically only processes the first 5,000
to 10,000 items; the complete list of database options and the maximum items processed is
PubMed Help

available.

Use the Related information abstract portlet to link to other related NCBI databases for the
selected citation.

The Abstract format supplemental information, available for MEDLINE indexed citations,
links to PubMed, MeSH and other NCBI databases.

Note: To simultaneously search all NCBI databases choose All Databases from the Search
pull-down menu, enter a search term, and then click Search.

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Finding related resources using LinkOut

Most PubMed records include LinkOut resources to a variety of web sites including publishers,
aggregators, libraries, biological databases, and sequence centers. LinkOut resources link to
providers’ sites to obtain the full-text of articles or related information, e.g., consumer
health. There may be a charge to access the text or information.
PubMed Help

To display the LinkOut resources open the LinkOut section included at the end of the abstract
format. The LinkOut section is available when you display a single record in the abstract format.

To find citations with links to free full-text articles, click the Filter your results Free Full Text
link.

To find citations with links to full-text articles, enter search terms followed by AND full text
[sb].

More information about Links:

• LinkOut resource categories have been selected by the LinkOut provider.
• The current list of LinkOut providers is available.
PubMed Help

• A publisher's icon link may display on the abstract format if they have electronically
provided their citation data to NCBI. Links are only available for publishers that are
participating in LinkOut; publishers are responsible for providing working links.
• Use My NCBI to customize your LinkOut preferences to display only links of interest
to you.

Displaying References for a PubMed Central article

The PubMed abstract may include References for this PMC Article for full text articles in
PubMed Central. The link displays the PubMed references for the PMC article.

Finding PubMed Central articles that have cited an article

PubMed Help

The PubMed abstract may include a Cited by PubMed Central articles portlet for PubMed
citations cited by PubMed Central articles. The Cited in PubMed Central portlet lists the articles
in PubMed Central for the cited PubMed citation.

Finding Bookshelf books that have cited an article

The abstract Cited in Books link is available for PubMed citations cited in the bibliography
of a Book in the Bookshelf.

Reporting broken or problem links

LinkOut links are supplied by the LinkOut providers. Publishers who electronically supply
their data to PubMed may include an icon that links to a site providing the full-text. Corrections
PubMed Help

and changes to links are made by the providers and are their responsibility.

To report problem links or inquire about online journal subscriptions, contact the provider
directly. Contact information is typically available at a provider's web site.

Displaying the Search Details

PubMed may modify or add additional search terms to your search to optimize retrieval.

See the results page Search details box to view your search as it was translated using automatic
term mapping and search rules.

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 Page 33

More information about Details:

• The Query Translation box shows the search strategy used to run the search.
– To edit the search in the Query Translation box, add or delete terms and then
click Search.
– Click URL to display the current search as a URL to bookmark for future use.
PubMed Help

Searches created using History numbers can not be saved using the URL
feature.
• The Result number link displays the total number of citations for the search.
• Translations details how each term was translated using PubMed's search rules and
syntax.
• User Query shows the search terms as you entered them in the search box and any
syntax errors with the query.
• If your last action was displaying a related citation set or selected items in another
format, Details will indicate this rather than the last query.
Saving and E-mailing Results and Searches
PubMed Help

Section Contents
• Saving citations temporarily using the Clipboard or indefinitely using My NCBI
Collections including Favorites Tutorial

• Saving citations as a text file

• Exporting citations into citation management software
• E-mailing citations
• Saving searches with My NCBI
• Saving searches as RSS (Really Simple Syndication) feeds
• Creating a URL to bookmark your search
PubMed Help

Saving citations temporarily using the Clipboard

The Clipboard provides a place to collect selected citations from one or several searches. The
Clipboard will be lost after 8 hours of inactivity on PubMed or other NCBI databases.

You may also save your search results indefinitely using My NCBI Collections.

To add citations to the Clipboard:

1 In your search results, use the citation check boxes to select citations. To save all your
citations do not click any check boxes.
2 Use Send to, and select Clipboard.
PubMed Help

3 To view your selections, click the Clipboard portlet items link.

To delete citations from the Clipboard:
• Use the Remove from clipboard link to delete individual items, or use the check boxes
to select items to delete, and then click the Remove selected items link.
• To delete all citations from the Clipboard, do not select any items, click the Remove
all link.
More information about the Clipboard:
• Citations in the clipboard display item in clipboard.

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 Page 34

• The clipboard portlet displays the total number of items in the clipboard. A link to the
clipboard is also available under the homepage PubMed Tools.
• The maximum number of items that can be sent to the clipboard is 500. If you select
Ccipboard from send to without selecting citations, PubMed will add all (up to 500
citations) of your search results to the clipboard.
PubMed Help

• The clipboard will not add a citation that is currently in the clipboard; it will not create
duplicate entries.
• Your web browser must be set to accept cookies to use the clipboard.
• Citations in the clipboard are represented by the search number #0, which may be used
in Boolean search statements. For example, to limit the citations you have collected in
the Clipboard to English language articles, use the following search: #0 AND english
[la]. This does not affect or replace the Clipboard contents.

Saving citations as a text file

1 In your search results, use the citation check boxes to select citations. You may move
to other pages to continue your selections. If you do not make any selections, PubMed
PubMed Help

will save the entire retrieval.

2 From Send to, select File.
3 Your web browser will prompt you to save the PubMed search results in a file on your
computer.
More information about saving citations to a file:
• Saving a large retrieval may take several minutes.
• The default for the send to file feature is to save the entire retrieval unless you select
specific citations. For example, if you use send to file for results displaying 1 to 20 of
2,356, your saved file will contain all 2,356 citations.
• Select format CSV to generate an abbreviated summary citation in a comma separated
PubMed Help

file.
• To save citations in HTML format, use the Save as... function of your browser. Change
the file extension to html. When saving as HTML, only those citations displayed on
the page will be saved; therefor, consider changing the number of items per page.

Exporting citations into citation management software

To export citations into a citation management software program such as EndNote, Reference
Manager, and ProCite:
1 In your search results, use the citation check boxes to select citations. To export all
the citations do not select any citations.
2 From Send to, select Citation manager.
PubMed Help

3 Import this saved file into your citation management program.

Questions regarding commercial software packages should be directed to the respective
companies.

E-mailing citations
1 In your search results, use the check boxes to select citations. To e-mail all citations
displayed on the page, do not make any selections.
2 From Send to, select E-mail.
3 Choose selections for Format, Sort by Number to send, and start from citation.

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 Page 35

4 Enter an e-mail address. You may also enter additional text that will be included in
the e-mail.
5 Click E-mail. The system returns you to your results page and displays a confirmation
e-mail sent message.
Note: Use My NCBI to create an automatic e-mail update for searches.
PubMed Help

Your PubMed results will be sent from the NCBI automatic mail server, Sent by NCBI
[nobody@ncbi.nlm.nih.gov], with a "Subject" of PubMed Search Results. Do not reply to this
message. This is not a functioning customer service e-mail address.

More information about e-mailing citations:

• You may e-mail up to 200 items at a time to a single e-mail address.
• The search will be included in your results email, or a notation indicating the number
of selected items.

Saving searches as RSS (Really Simple Syndication) feeds

You can create a search as an RSS feed. An RSS reader is required to use this service.
PubMed Help

To retrieve new items for your search since the last time you were connected to your RSS
reader:
1 Run a search in PubMed.
2 Click RSS located above the Search box.
3 You may edit the feed name and limit the number of items displayed, and then click
Create RSS. If the number of citations retrieved is greater than the number of items
displayed the feed will include a link to display the complete PubMed retrieval.
4 Click the XML icon to display the XML and copy and paste the URL into the subscribe
form in your RSS reader. web browsers and RSS readers may use different options
PubMed Help

to copy the feed.

PubMed RSS feeds use the My NCBI “What’s New” strategy for updating searches.

Creating a URL to bookmark your search

You can create a URL with your search terms that can be bookmarked in your web browser
for future use, see creating a web link to PubMed.
1 Alternatively, run a search and then click See more in results page search details box.
2 Click URL below the Query Translation box.
3 Bookmark the URL using your web browser function. You can also copy the URL
from the web browser’s URL address box.
PubMed Help

More information about creating a bookmark:

• Searches that were created using a search statement number in Advanced History (e.g.,
#1 OR #2 AND human[mh]) can not be saved using the URL feature because search
will be lost when History expires.
• After saving the bookmark, you may want to use your web browser's edit functions to
rename the bookmark.
My NCBI
My NCBI saves searches, results, your bibliography, and features an option to automatically
update and e-mail search results from your saved searches.

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My NCBI preferences includes storing and changing your e-mail address, highlighting search
terms, opening the abstract display supplemental data by default, and turning off the auto
suggest feature.

Additional features include filtering search results, managing recent activity, and setting a
LinkOut icon, document delivery services, and outside tool preferences.
PubMed Help

Click the My NCBI Sign In link, located at the top right of the page header, to sign into My
NCBI or register for an account.

How to Get the Journal Article

Tutorial

PubMed does not include the full text of journal articles; however, click the icon in the top
right corner of the abstract display to link to the full text, if available.

In addition, the abstract display may include a LinkOut – more resources link located at the
PubMed Help

bottom of the display, with additional full text sources.

Additional tips for obtaining articles.

Section Contents
• Many articles are available for free.
• If you are a physician, researcher, or health professional, utilize your affiliation with
a medical library or institution.
• If you are a member of the general public or not affiliated with a medical library or
institution, try finding free copies, check with your local library, or go directly to the
publisher.
PubMed Help

Free copies of some articles may be obtained in these ways:

Free full text Filter
Use the filter sidebar and click the Free full text available link to narrow your results to
resources that are available for free on the web.

PubMed Central
Click the Asbtract display “Free in PMC” icon to link to the article in PubMed Central.

PubMed Central (PMC) is the U.S. National Institutes of Health (NIH) free digital archive of
biomedical and life sciences journal literature.
PubMed Help

Free from the publisher

Click the free full text icon on the abstract format. Some publishers will provide free access to
articles after you register as a guest.

Note: When you click a full text icon or link in PubMed, you leave PubMed and are directed
to the full text at an external provider's site. NCBI does not hold the copyright to this material,
and cannot give permission for its use. Users should review all copyright restrictions set forth
by the full text provider before reproducing, redistributing, or making commercial use of
material accessed through LinkOut.

PubMed Help
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Please see the Copyright and Disclaimers page for additional information.

If you are affiliated with a hospital, university, or other institution

• Your local medical library is your best option. If you see icons for your library on the
abstract view this indicates that your library provides a link to the article, or has the
journal in its collection.
PubMed Help

Example library icons:

If your library does not have access to the article you need, ask a librarian about ordering the
article from another institution.
• If you need articles on a routine basis consider using the Send to Order option.
First, you must register with a delivery service.
1 The default article order service is the NLM-sponsored Loansome Doc service. This
service is recommended for health professionals associated with a medical library,
PubMed Help

and provides the full-text of an article from participating medical libraries. Local fees
and delivery methods will vary.
2 If you are not affiliated with a medical library or want to change your document
delivery provider to another service use the My NCBI Document Delivery.
After registering for Loansome Doc or another document ordering service use Send to
Order to place the order:
1 Click the check box next to each citation to order. You may move to other pages
within your results to select additional citations.
2 Click Send to, select Order.
3 Follow the on-screen directions.
PubMed Help

Note: For information on the medical libraries in your area (or country) that provide articles
via Loansome Doc check the frequently asked questions (FAQ) including: How do I find an
ordering library?

Local library
Some local libraries have copies of medical journals or can get a copy of an article for you.
Ask your local librarian about inter-library loan options and charges.

For information on the medical libraries in your area (or country) that provide articles via the
NLM-sponsored Loansome Doc service check the frequently asked questions (FAQ)
including: How do I find an ordering library?
PubMed Help

Direct from publisher

Journal publishers or related organizations may provide access to articles for a fee or may be
free after registering as an individual or guest. When available, icons to these sources can be
found on the Abstract format.

Additional links to articles may be available under LinkOut on the Abstract display.

Example abstract icons:

PubMed Help
 Page 38
PubMed Help

Other Services Including the MeSH and NLM Catalog Databases

Section Contents

Searching by using the MeSH database

Searching for journal information in the NLM Catalog

Using PubMed Mobile

Creating a web link to search PubMed

PubMed Help

Using the E-utilities programming tools

Using the Batch Citation Matcher

Using Batch Entrez

Searching by using the MeSH Database

Tutorial

MeSH (Medical Subject Headings) is the NLM controlled vocabulary thesaurus used for
indexing PubMed citations.
PubMed Help

Use the MeSH database to find MeSH terms, including Subheadings, Publication Types,
Supplementary Concepts and Pharmacological Actions, and then build a PubMed search. The
MeSH database can be searched by MeSH term, MeSH Entry Term, Subheading, Publication
Type, Supplementary Concept, or MeSH Scope Note.

More information about the MeSH database:

• An autocomplete feature is available from the search box.
• Search results are displayed in relevance-ranked order, therefore, when a user’s search
exactly matches a MeSH Term, that Term is displayed first.
• Click the MeSH term from the Summary display or choose Full from the Display
PubMed Help

Settings menu to view additional information and search specifications, such as

Subheadings, restrict to Major MeSH Topic, or exclude terms below the term in the
MeSH hierarchy.
• Year Introduced is the year the term was added to MeSH. If more than one year is
shown, the term was available for indexing back to the earliest year noted. Articles are
indexed using the vocabulary in place at the time of indexing, therefore, the year
introduced for a term and the date of publication of a citation indexed with that term
may not agree.
Launching PubMed searches from MeSH

PubMed Help
 Page 39

To build a PubMed search from MeSH, run a search, select terms using the check boxes, and
then click "Add to search builder" in the PubMed search builder portlet. You may continue
searching and including additional terms to the PubMed search builder using the “Add to search
builder” and Boolean pull-down menu. When you are finished, click “Search PubMed.”

Searching for journal information in the NLM Catalog

PubMed Help

The NLM Catalog includes information about the journals in PubMed and the other NCBI
databases.

Click Journals in the NCBI Databases on the homepage of NLM Catalog or PubMed to limit
your NLM Catalog results to the subset of journals that are referenced in NCBI database
records.

See the NLM Catalog help for additional information.

Other journal resources include:

• PubMed journals with links to full-text
PubMed Help

• List of all journals included in PubMed via FTP

• List of Serials Indexed for Online Users

Using PubMed Mobile

PubMed Mobile provides a simplified mobile friendly web interface to access PubMed.
PubMed Mobile includes the same search functionality and content as Standard PubMed, that
is, all search terms and fields work similarly.

PubMed Mobile is also useful for users who require special adaptive equipment to access the
web.

Using the E-utilities programming tools

PubMed Help

E-utilities are tools that provide access to data outside of the regular NCBI web search interface.
This may be helpful for retrieving search results for use in another environment.

Using the Batch Citation Matcher

Use the Batch Citation Matcher to retrieve PMIDs (PubMed IDs) for multiple citations in batch
mode. The Matcher requires you enter the bibliographic information (journal, volume, page,
etc.) in a specific citation format.

Using Batch Entrez

Use Batch Entrez to upload a file of PMIDs directly to PubMed.
PubMed Help

Appendices
Section Contents

How PubMed works: automatic term mapping

PubMed coverage

Consumer health

Error messages

PubMed Help
 Page 40

Cookies

Search field descriptions and tags

MeSH Subheadings
PubMed Help

MeSH Subheading hierarchies

PubMed Publication Types

Stopwords

MEDLINE display format

NLM author indexing policy

Grant code and institute abbreviations used in grant numbers

PubMed character conversions

PubMed Help

Clinical Queries Filters

Computation of Related Citations

PMID to PMC ID converter

Batch Citation Matcher Help

PubMed usage data

How PubMed works: automatic term mapping

Untagged terms that are entered in the search box are matched (in this order) against a
PubMed Help

MeSH (Medical Subject Headings) translation table, a Journals translation table, the Full
Author translation table, Author index, the Full Investigator (Collaborator) translation table
and an Investigator (Collaborator) index.

When a match is found for a term or phrase in a translation table the mapping process is
complete and does not continue on to the next translation table.

1. MeSH translation table

The MeSH Translation Table contains:
• MeSH terms
• The See-Reference mappings (also known as entry terms) for MeSH terms
PubMed Help

• MeSH Subheadings
• Publication Types
• Pharmacologic action terms
• Terms derived from the Unified Medical Language System (UMLS) that have
equivalent synonyms or lexical variants in English
• Supplementary concept (substance) names and their synonyms.
If a match is found in this translation table, the term will be searched as MeSH (that includes
the MeSH term and any specific terms indented under that term in the MeSH hierarchy), and
in all fields.

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For example, if you enter child rearing in the search box, PubMed will translate this search to:
"child rearing"[MeSH Terms] OR ("child"[All Fields] AND "rearing"[All Fields]) OR "child
rearing"[All Fields]

If you enter a MeSH Term that is also a Pharmacologic Action PubMed will search the term
as [MeSH Terms], [Pharmacologic Action], and [All Fields].
PubMed Help

If you enter an entry term for a MeSH term the translation will also include an all fields search
for the MeSH term associated with the entry term. For example, a search for odontalgia will
translate to: "toothache"[MeSH Terms] OR "toothache"[All Fields] OR "odontalgia"[All
Fields] because Odontalgia is an entry term for the MeSH term toothache.

Substance name mappings do not include a mapping for individual terms in a phrase, e.g.,
IL-22 will not include IL[All Fields AND 22[All Fields].

MeSH term mappings that include a standalone number or single character do not include a
mapping for individual terms in a phrase, e.g., Protein C will not include Protein[All Fields]
or C[All Fields].
PubMed Help

More information about automatic term mapping:

• See the results Search details to verify how your terms are translated. If you want to
report a translation that does not seem accurate for your search topic, please e-mail the
information to the NLM Help Desk.

2. Journals translation table

The Journals translation table contains the:
• full journal title
• title abbreviation
• ISSN number.
PubMed Help

These will automatically map to the journal abbreviation that is used to search journals in
PubMed and in all fields. For example, a search for endocrine pathology will translate to:
"Endocr Pathol"[Journal] OR ("endocrine"[All Fields] AND "pathology"[All Fields]) OR
"endocrine pathology"[All Fields]

3. Full Author translation table

The full author translation table includes full author names for articles published from 2002
forward, if available. Enter a full author name in natural or inverted order, e.g., julia s wong
or wong julia s.

More information about full author searching:

PubMed Help

• A comma following the last name for searching is optional. For some names, however,
it is necessary to distinguish which name is the last name by using the comma following
the last name, e.g., james, ryan.
• Omit periods after initials and put all suffixes at the end, e.g., vollmer charles jr
• Initials and suffixes are not required, if you include a middle initial or suffix, you will
only retrieve citations for articles that were published using the middle initial or suffix.
• To distinguish author initials that may match a full author name use the [fau] search
tag, e.g., peterson do[fau].

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4. Full Investigator (Collaborator) translation table

If the term is not found in the above tables, except for Full Author, and is not a single term,
the full investigator table is consulted for a match. The full investigator (collaborator)
translation table includes full names, if available. Enter a full investigator name in natural or
inverted order, e.g., harry janes or janes harry.
PubMed Help

5. Author index
If the term is not found in the above tables, except for Full Author or Full Investigator, and is
not a single term, PubMed checks the author index for a match. PubMed automatically truncates
a search for an author's name to account for varying initials, e.g., o'brien j retrieves o'brien ja,
o'brien jb, o'brien jc jr, as well as o'brien j.

When combining multiple authors, to avoid a match with full author names, include initials or
use the [au] search tag, e.g., ryan[au] james[au]. Author names comprised of only stopwords,
e.g., as a, are not searched as authors if they are part of phrase, chemical burn as a danger,
unless the search only includes the author name, e.g., as a.
PubMed Help

6. Investigator (Collaborator) index

If the term is not found in the above tables, except for Full Author, Author, or Full Investigator,
and is not a single term, PubMed checks the investigator index for a match.

7. If no match is found?
PubMed breaks apart the phrase and repeats the above automatic term mapping process until
a match is found. PubMed ignores stopwords in searches.

If there is no match, the individual terms will be combined (ANDed) together and searched in
all fields.

Consumer Health
PubMed Help

The National Library of Medicine cannot provide specific medical advice. NLM urges you to
consult a qualified health care professional for answers to your medical questions. NLM does
not have pamphlets or other materials to mail.

PubMed Health offers up-to-date information on diseases, conditions, drugs, treatment options,
and healthy living, with a special focus on comparative effectiveness research from institutions
around the world

Error Messages
System Error Messages
Please provide your IT staff with the technical browser advice for NCBI web pages to ensure
PubMed Help

your browser, firewall, and servers are enabled for JavaScript, cookies, pop-ups, and HTTP
1.1. Antivirus software may affect page caching which can result in unexpected page expired
messages. Also, nlm.nih.gov should be added as a browser exception and be considered a
trusted site by your system and network. You may have to delete your browser's cache
(temporary files) before trying to access PubMed again.

Typographical Errors
Citations that carry the tag, [PubMed - in process] or [PubMed - as supplied by publisher] have
not yet gone through the NLM quality control procedures and indexing process. It is during
this process that errors are identified and corrected. It is not necessary to notify NLM of an

PubMed Help
 Page 43

error at this stage. However, if the error is still present when the above tags are no longer on
the citation, please report it to the NLM Help Desk and include the information below (or as
much as possible).
• The journal name, volume, issue, and page number.
• The article title, or the PMID number (e.g., PMID: 1234567).
PubMed Help

• The correct name using the format, last name initials (e.g., Jones JA).
Your report will be forwarded to the NLM Quality Assurance for further investigation. If a
change to the database is warranted, the citation will be corrected. Please understand that
due to the large volume of requests we are unable to answer individual error reports.

NLM leases its data to vendors around the world. Other products and services will not
necessarily immediately reflect corrections made to records at NLM. If you search MEDLINE
through a vendor's system, please contact your vendor about their maintenance schedules.

The National Library of Medicine (NLM) displays the author's name as it appears in the article
at the time of publication, only the last name plus the first two initials (e.g., Fauci AS) are used.
If the author's name was printed incorrectly at the time of publication, then the journal in which
PubMed Help

the article appeared must publish an erratum before NLM will make the correction in
MEDLINE. If this is the case, please contact the journal publisher.

It is NLM policy that errata are acknowledged only if they are printed in a citable form; that
is, an erratum notice must appear on a numbered page in the journal that originally published
the article. Error notices that are inserted unbound into a journal issue or "tipped in" will not
be considered part of the permanent bibliographic record. NLM does not make changes in the
database in response to letters from authors or editors, unless such letters indicate that a
substantive published erratum is forthcoming.

For additional information on how NLM handles errors, please review the NLM Errata,
Retraction, Duplicate Publication, and Comment Policy fact sheet.
PubMed Help

PubMed Coverage
PubMed provides access to bibliographic information that includes MEDLINE, as well as:
• The out-of-scope citations (e.g., articles on plate tectonics or astrophysics) from certain
MEDLINE journals, primarily general science and chemistry journals, for which the
life sciences articles are indexed for MEDLINE.
• Citations that precede the date that a journal was selected for MEDLINE indexing.
• Some additional life science journals that submit full text to PubMed Central and
receive a qualitative review by NLM.
• Citations for the NCBI Bookshelf collection.
PubMed Help

For additional information, please see the NLM Fact Sheet: What's the Difference Between
MEDLINE and PubMed?

MEDLINE
MEDLINE is the NLM premier bibliographic database that contains references to journal
articles in the life sciences with a concentration on biomedicine. MEDLINE records are
indexed with NLM Medical Subject Headings (MeSH). The database contains citations from
the late 1940s to the present, with some older material. New citations that have been indexed
with MeSH terms, publication types, GenBank accession numbers, and other indexing data are
available daily (Tuesday through Saturday) and display with the tag [PubMed - indexed for
MEDLINE].

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 Page 44

In Process Citations
PubMed's in-process records provide basic citation information and abstracts before the
citations are indexed with NLM MeSH Terms and added to MEDLINE. New in-process records
are available in PubMed daily (Tuesday through Saturday) and display with the tag [PubMed
- in process].
PubMed Help

Publisher-Supplied Citations
Citations received electronically from publishers appear in PubMed with the tag [PubMed - as
supplied by publisher]. New publisher supplied citations are available in PubMed Tuesday
through Saturday. Most citations progress to in-process, and then to indexed for MEDLINE.
However, not all citations will be indexed for MEDLINE and therefore will retain either the
tag [PubMed - as supplied by publisher] or [PubMed]. Publishers may submit citations for
articles that appear on the web in advance of the journal issue's release. These ahead-of-print
citations also display the tag [Epub ahead of print].

Cookies
A "cookie" is information stored by a web site server on your computer. See the NLM Privacy
Policy for additional information.
PubMed Help

In the case of PubMed, it is information about your interactions that may be needed later to
perform a function. Cookies placed by PubMed are removed from your computer after a set
time period unless you choose to use a persistent cookie with the My NCBI automatic sign in
function.

To use these interactive features you need to enable cookies on your computer. Consult your
browser's help for information on enabling cookies.

If you have problems using cookie-dependent features of PubMed, even after enabling cookies,
possible reasons may include:
• Cookies are blocked by your provider or institution. Check with your Internet provider
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and/or the system administrator at your institution to see if cookies can be accepted.
Even if you have them enabled in your web browser, if they are blocked by your
provider or institution (e.g., by a firewall, proxy server, etc.), cookie-dependent
features of PubMed won't work.
• Your computer's date and time settings are incorrect. Check your computer's time
settings to ensure that they are correct.

MeSH Subheadings
See the MeSH Subheadings and scope notes and allowable categories on the NLM website.

MEDLINE display format

PubMed Help

The MEDLINE Display Format tags table defines the data tags that compose the PubMed
MEDLINE format. The tags are presented in alphabetical order. Some of the tags (e.g., CIN)
are not mandatory and therefore will not be found in every PubMed MEDLINE format. Other
tags (e.g., AU, MH, and RN) may occur multiple times in one record. This format is available
for exporting citations into a citation management software program.

Not all fields are searchable in PubMed. See Search Field Descriptions and Tags.

NLM Author Indexing Policy

NLM author indexing policy is as follows:

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• 1966 - 1984: MEDLINE did not limit the number of authors.

• 1984 - 1995: The NLM limited the number of authors to 10, with "et al" as the eleventh
occurrence.
• 1996 - 1999: The NLM increased the limit from 10 to 25. If there were more than 25
authors, the first 24 were listed, the last author was used as the 25th, and the twenty-
PubMed Help

sixth and beyond became "et al."

• 2000 - Present: MEDLINE does not limit the number of authors.
More Information:
• Beginning in mid-2005, the policy restrictions on number of author names in past years
were lifted so that on an individual basis, a citation may be edited to include all author
names in the published article, regardless of the limitation in effect when the citation
was created.
• Effective with 1992 date of publication, letters are indexed individually with authors
rather than as an anonymous group.
• Until 1990, NLM transliterated up to five authors' Cyrillic or Japanese names to the
Roman alphabet. Since 1990, the first ten Cyrillic or Japanese names are transliterated.
PubMed Help

Chinese ideograms are not transliterated, but if transliterations of the authors’ names
are available in the journal article or table of contents, they are included in the citation,
even if that includes only one author in a multi-author article.

PubMed Character Conversions

Certain characters have special meaning in searches, others are converted to spaces.

Searches that include the following characters are translated as follows:

parentheses ( ) - used to create Boolean nesting

square brackets [ ] - search field tag qualification
ampersand & - Boolean operator AND
PubMed Help

pipe | - Boolean operator OR

forward slash / - MeSH/Subheading combinations
comma , - typically forces a space, e.g., a,b is translated to a, b
colon : - designates a range operation
double quotes " - used to force a phrase search
pound sign # - designates a History search statement when immediately followed by a number,
e.g., #1 AND cat
asterisk * - wildcard symbol for search term truncation, e.g., toxicol*

Characters converted to spaces in search queries:

exclamation mark !
PubMed Help

pound sign #
dollar sign $
percentage sign %
asterisk *
plus symbol +
minus symbol -
period .
semi-colon ;
angle brackets < >
equal sign =

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question mark ?
backslash \
caret ^
underscore _
curly brackets { }
approximately ~
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Clinical Queries Filters

Medical Genetics Filters
Systematic Reviews Search Filter
Clinical Queries using Research Methodology Filters
Category Optimized For Sensitive/ Specific PubMed Equivalent

((clinical[Title/Abstract] AND trial[Title/Abstract]) OR clinical trials[MeSH

sensitive/broad 99%/70% Terms] OR clinical trial[Publication Type] OR random*[Title/Abstract] OR
random allocation[MeSH Terms] OR therapeutic use[MeSH Subheading])
therapy
(randomized controlled trial[Publication Type] OR (randomized[Title/
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specific/narrow 93%/97%
Abstract] AND controlled[Title/Abstract] AND trial[Title/Abstract]))

(sensitiv*[Title/Abstract] OR sensitivity and specificity[MeSH Terms] OR

diagnos*[Title/Abstract] OR diagnosis[MeSH:noexp] OR diagnostic *
sensitive/broad 98%/74%
[MeSH:noexp] OR diagnosis,differential[MeSH:noexp] OR diagnosis
diagnosis
[Subheading:noexp])

specific/narrow 64%/98% (specificity[Title/Abstract])

(risk*[Title/Abstract] OR risk*[MeSH:noexp] OR risk *[MeSH:noexp] OR

sensitive/broad 93%/63%
cohort studies[MeSH Terms] OR group*[Text Word])
etiology
((relative[Title/Abstract] AND risk*[Title/Abstract]) OR (relative risk[Text
specific/narrow 51%/95% Word]) OR risks[Text Word] OR cohort studies[MeSH:noexp] OR (cohort
[Title/Abstract] AND stud*[Title/Abstract]))
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(incidence[MeSH:noexp] OR mortality[MeSH Terms] OR follow up studies

sensitive/broad 90%/80% [MeSH:noexp] OR prognos*[Text Word] OR predict*[Text Word] OR course*
[Text Word])
prognosis
(prognos*[Title/Abstract] OR (first[Title/Abstract] AND episode[Title/
specific/narrow 52%/94%
Abstract]) OR cohort[Title/Abstract])

(predict*[tiab] OR predictive value of tests[mh] OR scor*[tiab] OR observ*

sensitive/broad 96%/79%
[tiab] OR observer variation[mh])
clinical prediction guides
specific/narrow 54%/99% (validation[tiab] OR validate[tiab])

The Clinical Queries search filters are based on the work of Haynes RB et al.

Medical Genetics Search Filters

PubMed Help

Category PubMed Equivalent

Diagnosis (Diagnosis AND Genetics)

Differential Diagnosis (Differential Diagnosis[MeSH] OR Differential Diagnosis[Text Word] AND Genetics)

Clinical Description (Natural History OR Mortality OR Phenotype OR Prevalence OR Penetrance AND Genetics)

Management (therapy[Subheading] OR treatment[Text Word] OR treatment outcome OR investigational therapies AND Genetics)

Genetic Counseling (Genetic Counseling OR Inheritance pattern AND genetics)

Molecular Genetics (Medical Genetics OR genotype OR genetics[Subheading] AND genetics)

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(DNA Mutational Analysis OR Laboratory techniques and procedures OR Genetic Markers OR diagnosis OR testing OR
Genetic Testing
test OR screening OR mutagenicity tests OR genetic techniques OR molecular diagnostic techniques AND genetics)

((Diagnosis AND genetics) OR (Differential Diagnosis[MeSH] OR Differential Diagnosis[Text Word] AND genetics) OR
(Natural History OR Mortality OR Phenotype OR Prevalence OR Penetrance AND genetics) OR (therapy[Subheading] OR
PubMed Help

treatment[Text Word] OR treatment outcome OR investigational therapies AND genetics) OR (Genetic Counseling OR
All
Inheritance pattern AND genetics) OR (Medical Genetics OR genotype OR genetics[Subheading] AND genetics) OR (DNA
Mutational Analysis OR Laboratory techniques and procedures OR Genetic Markers OR diagnosis OR testing OR test OR
screening OR mutagenicity tests OR genetic techniques OR molecular diagnostic techniques AND genetics))

The genetics searches were developed in conjunction with the staff of GeneReviews: Genetic
Disease Online Reviews at GeneTests, University of Washington, Seattle.

Computation of Related Citations

The neighbors of a document are those documents in the database that are the most similar to
it. The similarity between documents is measured by the words they have in common, with
some adjustment for document lengths. To carry out such a program, one must first define what
a word is. For us, a word is basically an unbroken string of letters and numerals with at least
PubMed Help

one letter of the alphabet in it. Words end at hyphens, spaces, new lines, and punctuation. The
132 common, but uninformative, words (also known as stopwords) are eliminated from
processing at this stage. Next, a limited amount of stemming of words is done, but no thesaurus
is used in processing. Words from the abstract of a document are classified as text words. Words
from titles are also classified as text words, but words from titles are added in a second time
to give them a small advantage in the local weighting scheme. MeSH terms are placed in a
third category, and a MeSH term with a subheading qualifier is entered twice, once without
the qualifier and once with it. If a MeSH term is starred (indicating a major concept in a
document), the star is ignored. These three categories of words (or phrases in the case of MeSH)
comprise the representation of a document. No other fields, such as Author or Journal, enter
into the calculations.
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Having obtained the set of terms that represent each document, the next step is to recognize
that not all words are of equal value. Each time a word is used, it is assigned a numerical weight.
This numerical weight is based on information that the computer can obtain by automatic
processing. Automatic processing is important because the number of different terms that have
to be assigned weights is close to two million for this system. The weight or value of a term is
dependent on three types of information: 1) the number of different documents in the database
that contain the term; 2) the number of times the term occurs in a particular document; and 3)
the number of term occurrences in the document. The first of these pieces of information is
used to produce a number called the global weight of the term. The global weight is used in
weighting the term throughout the database. The second and third pieces of information pertain
only to a particular document and are used to produce a number called the local weight of the
term in that specific document. When a word occurs in two documents, its weight is computed
PubMed Help

as the product of the global weight times the two local weights (one pertaining to each of the
documents).

The global weight of a term is greater for the less frequent terms. This is reasonable because
the presence of a term that occurred in most of the documents would really tell one very little
about a document. On the other hand, a term that occurred in only 100 documents of one million
would be very helpful in limiting the set of documents of interest. A word that occurred in only
10 documents is likely to be even more informative and will receive an even higher weight.

The local weight of a term is the measure of its importance in a particular document. Generally,
the more frequent a term is within a document, the more important it is in representing the

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content of that document. However, this relationship is saturating, i.e., as the frequency
continues to go up, the importance of the word increases less rapidly and finally comes to a
finite limit. In addition, we do not want a longer document to be considered more important
just because it is longer; therefore, a length correction is applied. This local weight computation
is based on the Poisson distribution and the formula can be found in Lin J and Wilbur WJ.
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The similarity between two documents is computed by adding up the weights (local wt1 × local
wt2 × global wt) of all of the terms the two documents have in common. This provides an
indication of how related two documents are. The resultant score is an example of a vector
score. Vector scoring was originated by Gerard Salton and has a long history in text retrieval.
The interested reader is referred to Salton, Automatic Text Processing, Reading, MA: Addison-
Wesley, 1989 for further information on this topic. Our approach differs from other approaches
in the way we calculate the local weights for the individual terms. Once the similarity score of
a document in relation to each of the other documents in the database has been computed, that
document's neighbors are identified as the most similar (highest scoring) documents found.
These closely related documents are pre-computed for each document in PubMed so that when
you select Related citations, the system has only to retrieve this list. This enables a fast response
time for such queries.
PubMed Help

Batch Citation Matcher Help

To retrieve PubMed PMIDs or PubMed Central IDs:
1 Enter each citation string on a separate line below, or create a file using the following
format:
journal_title|year|volume|first_page|author_name|your_key|

Fields must be separated by a vertical bar with a final bar at the end of the string.
2 Enter your email address. Email messages may take several minutes to process and
be sent to your email address.
3 If you created a file, click Browse to select it from your system directory.
PubMed Help

If a match is not found the citation string will display one of the following:
• INVALID_JOURNAL - The journal name is not a valid. See the journal lists or the
NLM Catalog to find the correct journal abbreviation.
• NOT_FOUND - The journal name is valid but the complete citation did not find a
match.
• AMBIGUOUS - The information provided matches more than one citation. Citation
information with 3 or fewer matches includes the PMIDs, and more than 3 matches
includes the total PMID match count. Use the Single Citation Matcher or ESearch to
retrieve all citations for searched fields.
Notes:
PubMed Help

• Select PMC from the database pull-down menu to change the default from PubMed.
• Enter author names without punctuation as smith jc. Initials are optional.
• Your key is any string you choose to tag the citation, it is returned unaltered.
• The journal title field may include the full journal title or the title abbreviation.
• Each citation field is searched starting with the journal title until a unique match is
found.

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• The journal title is a required field however you may omit other fields. If you omit
fields you must retain the vertical bars in the citation string. For example, if you omit
the volume number 88 from the first example below it should be entered as:
proc natl acad sci u s a|1991||3248|mann bj|P32022-1|

Example input:
PubMed Help

proc natl acad sci u s a|1991|88|3248|mann bj|P32022-1|

proc natl acad sci u s a|1992|89|3271|gould se|P26261-1|

proc natl acad sci u s a|1999|89|3271|gould se|P26261-1|

res microbiol|1992|143|467|ivey dm|P25966-1|

science|1987|235|182|palmenberg ac|P12296-2|

eschatology|1993|12|22|public jq|C12233-2|
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virology|1993|193|492|hardy me|Q02945-1|

virus genes|1992|6|393||P27423-1|

yeast|1992|8|253|sasnauskas k|P24813-1|

Example output:

proc natl acad sci u s a|1991|88|3248|mann bj|P32022-1|2014248

proc natl acad sci u s a|1992|89|3271|gould se|P26261-1|1565618

proc natl acad sci u s a|1999|89|3271||P26261-1|NOT_FOUND

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res microbiol|1992|143|467|ivey dm|P25966-1|1448623

science|1987|235|182|palmenberg ac|P12296-2|3026048

eschatology|1993|12|22||C12233-2|NOT_FOUND;INVALID_JOURNAL

virology|1993|193|492|hardy me|Q02945-1|8382410

virus genes|1992|6|393||P27423-1|1335631

yeast|1992|8|253|sasnauskas k|P24813-1|1514324
PubMed Help

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Journal/Citation Subsets
Subset Code Journal/Citation Subset

Abridged Index Medicus is a list created in 1970 of approximately 120 core clinical English language journals that corresponds
AIM
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to "Core clinical journals" journal category selection in filters.

D Dentistry journals

E Citations from bioethics journals or selected bioethics citations from other journals

H Health administration journals, non-Index Medicus

IM Index Medicus journals

K Consumer health journals

N Nursing journals

Q History of medicine journals and selected citations from other journals

QIS Citations from non-Index Medicus journals in the field of history of medicine
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S Citations from space life sciences journals and selected space life sciences citations from other journals

T Health technology assessment journals, non-Index Medicus

X AIDS/HIV journals (selected citations from other journals 1980-2000)

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Status Subsets
Status Tag How to Search Citation Status

PubMed - as supplied by publisher publisher[sb] NOT pubstatusnihms Citations recently added to PubMed via electronic submission
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NOT pubstatuspmcsd NOT pmcbook from a publisher, and are soon to proceed to the next stage,
PubMed - in process (see below). This tag is also on citations
received before late 2003 if they are from journals not indexed for
MEDLINE, or from a journal that was accepted for MEDLINE
after the citations' publication date. These citations bibliographic
data have not been reviewed.

PubMed - in process inprocess[sb] Citations bibliographic data will be reviewed and indexed, i.e.,
MeSH terms will be assigned (if the subject of the article is within
the scope of MEDLINE).

PubMed - indexed for MEDLINE medline[sb] Citations that have been indexed with MeSH terms, Publication
Types, Substance Names, etc., and bibliographic data have been
reviewed.

PubMed pubstatusnihms AND publisher[sb] Author manuscripts submitted to PMC that fall under the NIH
Public Access Policy.
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PubMed pubstatuspmcsd AND publisher[sb] Records for selective deposit articles in PMC. These are articles
published in non-MEDLINE journals where the publisher has
chosen to deposit in PMC only those articles that fall under the N
IH Public Access Policy..

PubMed pmcbook Book and book chapter citations available on the NCBI Bookshelf.

PubMed pubmednotmedline[sb] Citations that have been reviewed for accurate bibliographic data
but will not receive MEDLINE indexing, because they are for
articles in non-MEDLINE journals, or they are for articles in
MEDLINE journals but the articles are out of scope or they are
from issues published prior to the date the journal was selected for
indexing, or citations to articles from journals that deposit their
full text articles in PMC but have not yet been recommended for
indexing in MEDLINE.
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PubMed - OLDMEDLINE oldmedline[sb] This tag identifies citations in the OLDMEDLINE subset.
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Display Formats
Display Format Format Description

Summary This format may include: Authors, Corporate Authors, Title (Titles originally published in a language other than English are
PubMed Help

translated and displayed in brackets), Journal source, Review Publication Type, language if the article is not in English, "No
abstract available" notation, PMID, Comment/Correction links, and citation status. Summary also displays a link for Related
citations.
Note: Summary (text) uses the NISO and ISO reference standards documented in Citing Medicine.

Abstract This format may include: Journal Source, Comment/Correction links, Title, language if article is not in English, Authors,
Collaborators, Corporate Author, Author Affiliation, Abstract, Non-English language abstract, Author Keywords, Image
thumbnails from PMC articles, Publication Types (except for the Journal Article publication type), MeSH Terms, Personal
Name as Subject, Substances, Supplementary Concepts, Secondary Source databank accession numbers, Grant numbers,
PMID, and citation status. Search links are available from Journal Title Abbreviations, Authors, MeSH Terms, Publication
Types, Substances, Supplementary Concepts, Grant Support, Secondary Source ID, and Personal Name as Subject. Some fields
link to search results.
Note: The Abstract (text) format does not include MeSH data.

MEDLINE Two-character tagged field format (Table 8) for the complete record. Use this format to export citations into citation
management programs.
PubMed Help

XML EXtensible Markup Language tagged format is a standard maintained by the World Wide Web Consortium (W3C). Users
running scripts to downloading data in XML should use E-Utilities rather than the web version of PubMed. A document
describing the MEDLINE XML data element descriptions is available. PubMed XML includes a PubMed Data section with
publication status, dates, and article IDs not present in the MEDLINE XML:
PubStatus: pubmed = Entrez Date, medline = MeSH Date, entrez = Create Date

PMID List PMIDs (PubMed IDs)

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MeSH Subheadings
Abbreviation MeSH Subheading Abbreviation MeSH Subheading

AB Abnormalities MA Manpower
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AD Administration and Dosage ME Metabolism

AE Adverse Effects MT Methods

AG Agonists MI Microbiology

AA Analogs and Derivatives MO Mortality

AN Analysis NU Nursing

AH Anatomy and Histology OG Organization and Administration

AI Antagonists and Inhibitors PS Parasitology

BI Biosynthesis PY Pathogenicity
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BS Blood Supply PA Pathology

BL Blood PK Pharmacokinetics

CF Cerebrospinal Fluid PD Pharmacology

CS Chemical Synthesis PH Physiology

CI Chemically Induced PP Physiopathology

CH Chemistry PO Poisoning

CL Classification PC Prevention and Control

CO Complications PX Psychology

CN Congenital RE Radiation Effects

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CT Contraindications RA Radiography

CY Cytology RI Radionuclide Imaging

DF Deficiency RT Radiotherapy

DI Diagnosis RH Rehabilitation

DU Diagnostic Use SC Secondary

DH Diet Therapy SE Secretion

DE Drug Effects ST Standards

DT Drug Therapy SN Statistics and Numerical Data

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EC Economics SD Supply and Distribution

ED Education SU Surgery

EM Embryology TU Therapeutic Use

EN Enzymology TH Therapy

EP Epidemiology TO Toxicity

ES Ethics TM Transmission

EH Ethnology TR Transplantation

ET Etiology TD Trends

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GE Genetics US Ultrasonography

GD Growth and Development UL Ultrastructure

HI History UR Urine
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IM Immunology UT Utilization

IN Injuries VE Veterinary

IR Innervation VI Virology

IS Instrumentation

IP Isolation and Purification

LJ Legislation and Jurisprudence

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Publication Types
See complete list of Publication Types. Publication types found in PubMed are listed below.

Addresses
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Autobiography

Bibliography

Biography

Case Reports

Classical Article

Clinical Conference

Clinical Trial

Clinical Trial, Phase I

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Clinical Trial, Phase II

Clinical Trial, Phase III

Clinical Trial, Phase IV

Collected Works

Comment

Comparative Study

Congresses

Consensus Development Conference

Consensus Development Conference, NIH

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Controlled Clinical Trial

Corrected and Republished Article

Dictionary

Directory

Duplicate Publication

Editorial

English Abstract

Evaluation Studies
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Festschrift

Government Publications

Guideline

Historical Article

In Vitro

Interactive Tutorial

Interview

Introductory Journal Article

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Journal Article

Lectures

Legal Cases
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Legislation

Letter

Meta-Analysis

Multicenter Study

News

Newspaper Article

Overall

Patient Education Handout

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Periodical Index

Personal Narratives

Portraits

Practice Guideline

Publication Components

Publication Formats

Publication Type Category

Published Erratum

Randomized Controlled Trial

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Research Support, American Recovery and Reinvestment Act

Research Support, N.I.H., Extramural

Research Support, N.I.H., Intramural

Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S.

Research Support, U.S. Gov't, P.H.S.

Retracted Publication

Retraction of Publication

Review
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Scientific Integrity Review

Study Characteristics

Support of Research

Technical Report

Twin Study

Validation Studies

Video-Audio Media

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Webcasts
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Stopwords
Stopwords

A a, about, again, all, almost, also, although, always, among, an, and, another, any, are, as, at
PubMed Help

B be, because, been, before, being, between, both, but, by

C can, could

D did, do, does, done, due, during

E each, either, enough, especially, etc

F for, found, from, further

H had, has, have, having, here, how, however

I i, if, in, into, is, it, its, itself

J just
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K kg, km

M made, mainly, make, may, mg, might, ml, mm, most, mostly, must

N nearly, neither, no, nor

O obtained, of, often, on, our, overall

P perhaps, pmid

Q quite

R rather, really, regarding

S seem, seen, several, should, show, showed, shown, shows, significantly, since, so, some, such

T than, that, the, their, theirs, them, then, there, therefore, these, they, this, those, through, thus, to
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U upon, use, used, using

V various, very

W was, we, were, what, when, which, while, with, within, without, would

Note: Tagged stopwords will not be ignored, e.g., among[ti], and will probably retrieve no
results.
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MEDLINE Display
More Details: MEDLINE/PubMed Data Element (Field) Descriptions

Tag Name Description

PubMed Help

AB Abstract English language abstract taken directly from the published article

AD Affiliation Institutional affiliation and address of the first author

AID Article Identifier Article ID values supplied by the publisher may include the pii (controlled publisher identifier), doi
(digital object identifier), or book accession

AU Author Authors

BTI Book Title Book Title

CI Copyright Information Copyright statement provided by the publisher

CIN Comment In Reference containing a comment about the article

CN Corporate Author Corporate author or group names with authorship responsibility

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CON Comment On Reference upon which the article comments

CP Chapter Book chapter

CRDT Create Date The date the citation record was first created

CRF Corrected and republished from Final, correct version of an article

CRI Corrected and republished in Original article that was republished in corrected form

CTDT Contribution Date Book contribution date

CTI Collection Title Collection Title

DA Date Created Used for internal processing at NLM

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DCOM Completion Date NLM internal processing completion date

DEP Date of Electronic Publication Electronic publication date

DP Publication Date The date the article was published

DRDT Date Revised Book Revision Date

EDAT Entrez Date The date the citation was added to PubMed; the date is set to the publication date if added more than
1 year after the date published

EFR Erratum For Cites the original article needing the correction

EIN Erratum In Reference containing a published erratum to the article

ED Editor Book editors

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EN Edition Book edition

FAU Full Author Name Full Author Names

FED Full Editor Name Full Editor Names

FIR Full Investigator Full investigator or collaborator name

FPS Full Personal Name as Subject Full Personal Name of the subject of the article

GN General Note Supplemental or descriptive information related to the document

GR Grant Number Research grant numbers, contract numbers, or both that designate financial support by any agency
of the US PHS or other funding agencies

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GS Gene Symbol Abbreviated gene names (used 1991 through 1996)

IP Issue The number of the issue, part, or supplement of the journal in which the article was published

IR Investigator Investigator or collaborator

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IRAD Investigator Affiliation Affiliation investigator or collaborator

IS ISSN International Standard Serial Number of the journal

ISBN ISBN International Standard Book Number

JID NLM Unique ID Unique journal ID in the NLM catalog of books, journals, and audiovisuals

JT Full Journal Title Full journal title from NLM cataloging data

LA Language The language in which the article was published

LID Location ID The pii or doi that serves the role of pagination

LR Modification Date Citation last revision date

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MH MeSH Terms NLM Medical Subject Headings (MeSH) controlled vocabulary

MHDA MeSH Date The date MeSH terms were added to the citation. The MeSH date is the same as the Entrez date until
MeSH are added

OAB Other Abstract Abstract supplied by an NLM collaborating organization

OCI Other Copyright Information Copyright owner

OID Other ID Identification numbers provided by organizations supplying citation data

ORI Original Report In Cites the original article associated with the patient summary

OT Other Term Non-MeSH subject terms (keywords) either assigned by an organization identified by the Other
Term Owner, or generated by the author and submitted by the publisher

OTO Other Term Owner Organization that may have provided the Other Term data
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OWN Owner Organization acronym that supplied citation data

PB Publisher Publishers of Books & Documents citations

PG Pagination The full pagination of the article

PHST Publication History Status Date Publisher supplied dates regarding the article publishing process

PL Place of Publication Journal's (country only) or book’s place of publication

PMCR PMC Release Availability of PMC article

PMID PubMed Unique Identifier Unique number assigned to each PubMed citation

PRIN Partial Retraction In Partial retraction of the article

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PROF Partial Retraction Of Article being partially retracted

PS Personal Name as Subject Individual is the subject of the article

PST Publication Status Publication status

PT Publication Type The type of material the article represents

RF Number of References Number of bibliographic references for Review articles

RIN Retraction In Retraction of the article

RN EC/RN Number Includes chemical, protocol or disease terms. May also a number assigned by the Enzyme
Commission or by the Chemical Abstracts Service.

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ROF Retraction Of Article being retracted

RPF Republished From Article being cited has been republished or reprinted in either full or abridged form from another
source
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RPI Republished In Article being cited also appears in another source in either full or abridged form

SB Subset Journal or citation subset values representing specialized topics

SFM Space Flight Mission NASA-supplied data space flight/mission name and/or number

SI Secondary Source Identifier Identifies secondary source databanks and accession numbers of molecular sequences discussed in
articles

SO Source Composite field containing bibliographic information

SPIN Summary For Patients In Cites a patient summary article

STAT Status Tag Used for internal processing at NLM

TA Journal Title Abbreviation Standard journal title abbreviation

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TI Title The title of the article

TT Transliterated Title Title of the article originally published in a non-English language, in that language

UIN Update In Update to the article

UOF Update Of The article being updated

VI Volume Volume number of the journal

VTI Volume Title Book Volume Title

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Journal Lists
PubMed Journals NCBI Molecular Biology Database Journals PubMed and NCBI Molecular Biology Database Journals

Uncompressed Uncompressed Uncompressed

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GNU zip GNU zip GNU zip

UNIX Compress UNIX Compress UNIX Compress

PKZIP PKZIP PKZIP

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