"External Quality

Assessment in Medical
Laboratories" - differences
with other PT testing
programs

JC Libeer
Brussels, Belgium
EQA versus PT

The term PT in laboratory medicine is

commonly used in North America

– Proficiency testing (PT) focus essentially

on laboratory performance evaluations
especially for regulatory purposes
From EQAS to EQAP

EQAS: External Quality Assessment

Schemes

EQAP: External Quality Assurance
Programs
Olafsdottir E, Hellsing K, Steensland H, Terhunen R, Uldall A.
Adding new scopes to traditional EQA schemes emphasizig
quality improvement. Upsala J Med Sc 1994: 187-
187-183
EQAP

EQAP is an interlaboratory comparison designed and operated
to assure one or more of following aspects:
– Participant performance evaluation (analytical performance, test
interpretation, advice to the clinician on laboratory requests and
on diagnosis
– Vigilance of IVD’s
– Continuous education, training and help

The primary intention of the activities of an EQAP in laboratory

medicine shall be to support quality improvements of the service
provided by participating laboratories for the benefits of the
patients.

(IFCC Guidelines for the Requirements for the Competence of EQAP

organizers 2002)
Interlaboratory comparison
ISO 15189

5.6.4 The laboratory shall participate in
interlaboratory comparisons such as those
organized by external quality assessment schemes.
Laboratory management shall monitor the results of
external quality assessment and participate in the
implementation of corrective actions when control
criteria are not furfilled. Interlaboratory comparison
shall be in substantial agreement with ISO/IEC
Guide 43-
43-1.

External quality assessment programmes should, as

far as possible, provide clinically relevant challenges
that mimic patient samples and have the effect of
checking the entire examination process, including
pre-
pre- and post
post--examination procedures.
« Patient care in ISO
15189 »

Introduction: Medical laboratory
sevices are essential to patient care…

4.1.2: Medical laboratory services,
including appropriate interpretation
and advisory servies, shall be designed
to meet the needs of patients and all
clinical personnel responsible for
patient care
« Patient care in ISO
15189 »

4.12.4: Laboratory management shall
implement quality indicators for
systematically monitoring and evaluating the
laboratory’s contribution to patient care……..
care……..
Laboratory management shall ensure that
the medical laboratory articipates in quality
improvement activities that deal with
relevant areas and outcomes of patient care
« Patient care in ISO
15189 »

4.14.1: ………The internal audit shall
progressively address these elements
and emphasize areas critically
important to patient care

4.15.1: In order to ensure their
continuing suitability and effectiviness
in support of patient care,…
– i) quality indicators for monitoring the
laboratory’s contribution to patient care
« Patient care in ISO
15189 »
4.15.3: The quality and appropriateness of the
laboratory’s contribution to patient care
shall, to the extent possible, be monitored
and evaluated objectively.
5.2.1: The laboratory shall have space
allocated so that its workload can be
performed without compromising the quality
of work, quality control procedures, safety
of personnel or patient care services
« Patient care in ISO
15189 »
5.8: Reporting of results:
e) Date and time of primary sample collection,
when available and relevant to patient care,
care,
and time of receipt by the laboratory
5.8.7 The laboratory shall have procedures for
immediate notification of a physician (or
other clinical responsible for patient care)
care)
when examination results for critical
properties fall within established « alert » or
« critical » intervals.
« Patient care in ISO
15189 »

5.8.11 Laboratory management, in consultation
with the requesters, shall establish turnaround
times for each of its examinations. A turnaround
time shall reflect clinical needs.
….
This does not mean that the clinical personnel are
to be notified of all delays in examinations, but only
in those situations where the delay could
compromise patient care.
care.
« Patient care in ISO
15189 »

Annex B: Recommendations for
protection of laboratory information
systems (LIS)

Reference to « patient care » 4X

EQA/PT ORGANIZERS

Medical laboratories
Other type of
laboratories

Professional
International and

organisations national scientific

Scientific societies organisations
(institutions)

Governmental
organisations
Commercial
organisations

IVD manufacturers

Accreditation bodies
 Professional & Scientific
EQA organizers versus
commercial EQA organizers

Is there a specific role to play by

professional and scientific EQA
organisations?

Is there a specific role to play by IVD
manufacturers organizing EQA schemes?
EQA from IVD
manufacturers (1)

Organizer of regular EQA schemes
with several materials

Link with the producer of kits and
reagents

Extra service for users of the same
internal QC material

Only own QC materials are used

No real patient material
EQA from IVD
manufacturers (2)

Especially activity in clinical chemistry and
immunoassays

Large groups, in general good service

Free participation

Educational, no sanctions

Feedback from a steering committee
(expert board) ?

THESE SCHEMES FOCUS ON ANALYTICAL
QUALITY
“Non-commercial” EQA
“Non-
schemes
PT schemes External quality
assessment =>

Mandatory external quality

Linked to a licence assurance schemes

Can be mandatory or free

Repressive (sanctions)
Can be linked to a license

Acceptability limits
Essentially educational
based on “state of the
Dynamic: incentives for
art” quality improvement – tools

Static: no incentive for for problem related
schemes
quality improvement

(EQAP approach)

Follow--up: “the bad
Follow
and the good boys”
Inconvenience of PT
schemes

“Bad boys” are punished

Everybody is happy with the “good boys”
– But: are the good boys as good as they look?

“Impression” of the potential capability of

laboratories to perform these tests

No link with patient samples analysis
EQAP covers more than
EQA

Participant performance evaluation

Method performance evaluation

Contineous education tool

Analytical performance and clinical outcome
evaluation

Support for internal QC

Training & help

Promotion of standardisation efforts

Quality improvement of patient results &
interpretation

…..
EQAP covers more than
EQA: new item of interest
External Quality
Assurance Programs

Broad panel of schemes covering all
aspects of laboratory medicine
- Preparation of own control materials
Or
- Sharing sample preparation

- Attention for new fields, new tests

- Fields for which there is no interest from
“commercial” organizers
External Quality
Assurance Programs

MUST FOCUS ON CLINICAL OUTCOME AND
NOT ONLY ON ANALYTICAL RESULTS
– Including pre-
pre- and post analytical EQA
– Including difficult samples
– Mimic as much as possible patient samples
– Attention for quality management of new
applications ( POCT, NPT)
– Acceptability limits may be based on EBM,
biological requirements,..
Pre-analytical EQA:
Pre-
examples

Examination of sample deficiencies based on
data from participants (SEQC experience)

EQA on appropriate sample package

Paper challenges with a clinical case and
evaluation of an appropriate tests request

Distribution of not appropriate sample
material (these samples are expected not to
be analysed)
 Preanalytical quality control program –
an overview of results (2001
(2001–
–2005 summary)

105 LABORATORIES : 4.715.132 tubes  32.977 (0.699 %)

REJECTS

 EDTA/SERUM (75.6% of all samples)  55.8 % of all rejects

 81% of rejects due to :

 Specimen not received  37.5%
 HEMOLYSIS  29.3% = 9.662 samples !
 Clotted sample  14.4%

About 30% of ALL rejects due to HEMOLYSIS
Cecília Martínez-
Martínez-Brú et al. Clin Chem Lab Med (2008);
46
46,, 6; 849–
849–854 (SEQC)
Paper Challenge of
Accessioning Practices

A nasal swab is submitted to the laboratory with
clinical information “possible anthrax”. No other
information provided. What action would your
laboratory undertake with this sample?
Set--up and Culture.
Set 22%
A
Read at 24 hours.
Do not process. 0%
B Destroy swab.
Report: “Do not perform this test”.

Do not process. 34%

C Contact physician.
physician.
Do not process. Seal for public health. Contact 78%
D Public Health.
CMPT M013; November 2001
 Example of educational
EQAS
Cyclospora cayetanensis:
1997 1998 2000
N labs 255 263 239
Cyclospora 135 214 192
(52.9%) (81.4%) (80.3%)
No parasites 52 10 18
found (20.4%) (3.8%) (7.8%)

Results in the Belgian EQAS programmes

Appropriate EQA material

Performances of lyophilized materials

do not always reflect performances in
patient samples

Some materials are scarce (IgM
samples for serology)

Realistic patient material

Virtual microscopy samples
 Bias of cholesterol methods against the
RMV in lyophilised control samples
0

-2

-4

-6

-8

-10
-12
M1 M2 M3 All methods
Bias of cholesterol methods against the
RMV in frozen patient samples
7

0
M1 M2 M3 All methods
Post--Analytical EQA
Post

Interpretation of analytical results

Which information is given to the
clinician?

Correct use of reference values
Appropriate reference values
check

HbA1c: all methods in use are DCTT
converted after IFCC calibration
⇒Reference values should be the same in
all laboratories (4-
(4-6%)

Real life: reported reference values

3.0
3.0--5.8 3.5
3.5-- 4.5
4.5-- 5.1
5.1--
6.2 6.8 6.5
0.1
0.1--5.4 4.0
4.0-- 4.8
4.8-- 6.0
6.0--
6.0 6.0 8.0
Post--analytical EQAS
Post

Paper challenges on interpretation of results
Combined analytical and
post--analytical exercice
post
 EQAS for virology
Sample S/5339 and S/5340 were taken to the same
patient with an interval of 4 weeks; Pregnancy wish in the
scope of IVF for a woman, 35 years old. Request for CMV
diagnosis
Requested results:
On each sample: total antibodies, IgG, IgG avidity,
IgM
Test interpretation: positive,negative,borderline
Combined interpretation for both samples:
Negative
Seroconversion
Recent infection (< 3 months)
Infection > 3 months
Reactivity
Others
EQAS for hemato-
hemato-
oncology: example

Paper challenge with

Patient history and clinical context

Results of cell counting

Results of flow cytometry

Translocations
Problem-related EQA
Problem-
schemes

Schemes focus on different aspects of
the test so that participants can have
information on these aspects were
there is a problem
Problem related EQA:
Inversed EQA
sperm staining procedure

Send two smears for morphology

Collect stained smears

Define criteria for acceptable results

Evaluation of staining by 3 experts

Report to participants

No “commercial” scheme will do this!

Method performance
evaluation

QCMD survey NG08: two samples with
DNA from other Neisseria strains

N. lactamica in sample NG08-
NG08-06 en N.
cinerea in sample NG08-
NG08-09

All participants using Roche Amplicor
have false positive results for both
samples
EQA ON INTERFERENCE
BY HEMOLYSIS (B EQA)

Participants were asked to
- score for the presence of hemolysis:
absent (-
(-) – weak (+) – moderate (++) –
strong (+++)
- to report the H – index if available and the
instrument used

(Courtosy of Christel Van Campenhout and Nicole

Hamers)
 INFLUENCE OF HEMOLYSIS ON γGT (U/L)

DIFFERENT SYSTEMS (d=20%)

30
24,8 24 24,5
23
21 21,3 21
20 20
19
20
13,5 12,9

10

2,1

0
GGT Mixel. GGT Roche- GGT OCD GGT Siemens GGT Coulter GGT Roche-IFCC
SZASZ (Dade)
-10
-10,8
-13,0

-20 -19,4

NORMAL
-30 HEMOLYZED
DIF (%)
-35,7
-40 -38,6
A dream for EQA schemes of
the future?
EQA in hematology: case
2014/3

Clinical history

Samples

Data

Instructions for replying
Clinical history (example)

All materials were drawn from the

same patient: woman 79 years old.

Since a few weeks abdominal pain.
Routine examination revealed a
lymphocytosis.
Question (example)

Perform those analysis in order to give

relevant clinical information for the
clinician
Samples

(Serum tube)

EDTA blood tube

(Virtual samples)
EQA examinations

Flow cytometry: markers of

lymphocytosis
– T-cell markers performed
– Results
Available data

Report of the cell counting

– Select your analyzer
– View of the report
Virtual peripherical blood
smear
WBC differentiation in smear H 3456

details
WBC differentiation in smear H 3456

Lymphocytes:

A4c, A4d, A7a, B2e, ……………….;

Monocytes:

A6e, D2f,…

Every cell can be checked

by the EQAS organizer
details
Hidden additional
information
Clinical chemistry examinations and results

Bone marrow results or data

You may open one or more drawers and use the information.
Only open those that you consider as essential for your final
advice
Virtual bone marrow
smear
Information received by
the EQA organizer

Participant ID

Information on used technology for
the requested analytes performed on
the EQA samples

Results of analysis

Formulated final advice

Logging of opened drawer(s)
An important role can be played by