DESIGN OF
CLINICAL TRIALS
ANURADHA DAS- B007
ANTARA PAL- B013
ZOHA AHMED- B003
SAFIA SYEDA- B019
SANGYA SHAILY- BO18
Formulation of trials and experiment
Observational studies
Goal - Safety, efficacy, mechanism of
action
RANDOMIZED CONTROLLED TRIAL
Scientific experiment that aims to reduce certain
sources of bias when testing the effectiveness of new
treatments.
Experimental and control groups
Treatment efficacy is assessed in comparison to
control group
Limitation:
Time consuming
Expensive
l
BLIND CLINICAL TRIAL
Blinding is a procedure in which one or more parties in a trial are kept
unaware of which treatment arms participants have been assigned to.
▪ Blinding is used to prevent conscious or
unconscious bias.
▪ This is important because bias can affect
recruitment and allocation, care, attitudes,
assessments, etc.
▪ Sources of bias include:
▪ Patient being treated
▪ Clinical staff administering treatment
▪ Doctor assessing treatment
▪ Team interpreting trial results
Types of Blinding
Single Double Triple
Blinded Blinded Blinded
Single Blind
▪ A trial in which one party,
either the investigator or
participant, is unaware of
which treatment the
participant is taking. Also
called single-masked trial.
▪ Should be used when:
▪ Provides some control when
double blinding is impossible
▪ Used when the
experimental medicine and
control cannot be
manufactured identically
Double Blind
A clinical trial design in
which neither the
participants nor the study
staff know which participants
are receiving the
experimental medicine, and
which are receiving a
placebo (or another
therapy).
Double-blind trials are
thought to produce
objective results, since the
expectations of the doctor
and the participant do not
affect the outcome. Also
called double-masked trial.
Triple Blind
A triple blind trial
means that patients,
clinicians, data
collectors, outcome
adjudicators and data
analysts are denied
access to details of
group assignment.
The analyst is blinded
as to which treatment
is which helps to avoid
bias in the analysis of
results.
PLACEBO CONTROLLED STUDY
Placebo-controlled studies are a way of testing a medical therapy in which, in
addition to a group of subjects that receives the treatment to be evaluated, a
separate control group receives a sham ”placebo" treatment which is
specifically designed to have no real effect.
Negative control type
The purpose of the placebo group is to account for the placebo effect.
Intentionally inert placebo treatments can take many forms
1. Pills
2. Injection
3. Surgery
4. Medical Device
The use of placebos is a standard control component of most clinical trials
METHODS
Blinding - Blinding is the withholding of information from
participants which may influence them in some way until after
the experiment is complete.
Natural History Groups - subjects in a drug trial that receive no
treatment of any kind and whose illness is left to run its "natural"
course.
Indexing – Determining the degree to which the level of
responses of trials subject are higher or lower than other trials
of similar drugs
IMPLEMENTATION ISSUES
Adherence
Unblinding
OPEN LABEL TRIALS
• OPEN-LABEL FASHION, MEANING STUDY PARTICIPANTS AND
RESEARCHERS BOTH KNOW WHICH TREATMENT THE PATIENT IS RECEIVING.
• OPEN-LABEL IS THE OPPOSITE OF DOUBLE-BLIND WHEN NEITHER THE
RESEARCHER NOR THE PARTICIPANT KNOWS WHAT TREATMENT THE
PARTICIPANT IS RECEIVING.
• OPEN-LABEL TRIALS MAY BE APPROPRIATE FOR COMPARING TWO VERY
SIMILAR TREATMENTS TO DETERMINE WHICH IS MOST EFFECTIVE.
• AS PART OF THE DEVELOPMENT OF NEW TREATMENTS FOR ALOPECIA
AREATA, COMPANIES ARE CONDUCTING SEVERAL DIFFERENT TYPES OF
TRIALS TO EVALUATE INVESTIGATIONAL TREATMENTS, INCLUDING OPEN
LABEL TRIALS.
Researchers assessed the effectiveness of prazosin
combined with scorpion antivenom in assisting recovery
from scorpion sting. An open label randomised controlled
trial study design was used. The control treatment was
prazosin alone. The setting was a hospital and research
centre in Mahad, a region of India. Participants were
patients with grade 2 scorpion envenomation, older than 6
months, and with no cardiorespiratory or central nervous
system abnormalities.
In total, 70 patients were recruited and allocated to
treatment (35 to prazosin and scorpion antivenom, and 35
to prazosin alone) by block randomisation. After
randomisation, participants were aware which treatment
they had been allocated to
The researchers concluded that recovery from a scorpion
sting was hastened by simultaneous administration of
scorpion antivenom plus prazosin compared with prazosin
alone.
LONGITUDINAL STUDY
Longitudinal research is a type of
correlational research that involves
looking at variables over an extended
period of time. This type of study can take
place over a period of weeks, months, or
ev en years. In some cases, longitudinal
studies can last several decades.
They are generally observational in
nature, with quantitative and/or
qualitative data being collected on any
combination of exposures and outcomes,
without any external influenced being
applied.
This study type is particularly useful for
ev aluating the relationship between risk
factors and the dev elopment of disease,
and the outcomes of treatments over
different lengths of time.
Advantage
The benefit of this type of research is that it allows researchers to look at
changes over time. Because of this, longitudinal methods are particularly
useful when studying development and lifespan issues. Researchers can
look at how certain things may change at different points in life and
explore some of the reasons why these developmental shifts take place.
Disadvantage:
Longitudinal studies require enormous amounts of time
Longitudinal Studies Can Be Expensive
Because of this, these studies often have only a small group of subjects,
which makes it difficult to apply the results to a larger population..
Participants Tend to Drop Out Over time. This tendency for some
participants to be more likely to drop out of a study is known as selective
attrition. Participants might drop out for a number of reasons. Some might
move away from the area while others simply lose the motivation to
participate. Others might become housebound due to illness or age-
related difficulties, and some participants will pass away before the study is
concluded.
NATURAL HISTORY STUDY
Study that follows a group of people over time who have,
or are at risk of dev eloping, a specific medical condition or
disease.
To determine how specific factors, such as family history,
age, and occupational exposure, affect the development
or progression of the disease or condition.
By collecting health information over time to understand
how the medical condition or disease develops and to
give insight into how it might be treated.
A natural history study is often submitted when applying to
any regulatory agency to show the disease course for
untreated patients.
The natural history data is compared to the disease course
of patients given a proposed therapy to show the effects
of the therapy.
Used especially for rare diseases.
Gaucher Disease
