Measures of Dispersion and Variability: Range, QD, AD and SD
clinical trials types and design
1. 1
GUIDED BY
Prof.
Dr.P.M.GAIKWAD
M.Pharm, Ph.D
(Head, Dept of
Pharmacology)
COGUIDED BY
Prof.V.V.Nimbalkar
Dept. Of pharmacology
PRESENTED BY
Miss. Joshi Uttara L.
M.Pharm (sem II)
(Pharmacology)
Roll no.08
Dr. V.V.P.F’S COLLEGE OF PHARMACY
AHMEDNAGAR (2018-2019 )
3. What is clinical trials?
clinical trials (Human testing of a drug) are a set of procedure
in medical research and drug development that are conducted
to allow safety (or more specifically ,information about
adverse drug reaction ,adverse effects and efficacy data to be
collected for health interventions (e.g. drugs
,diagnostics,devices,therapy etc.)
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4. Treatment trials test experimental
treatments, new combinations of drugs,
or new approaches to surgery or
radiation therapy.
Prevention trials look for better ways to
prevent disease in people who
have never had the disease or to prevent a disease from
returning. These approaches may include medicines,
vaccines, vitamins, minerals, or lifestyle changes.
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5. Diagnostic trials are conducted to find better tests
or procedures for
diagnosing a particular disease or condition.
Screening trials test the best way to detect certain
diseases or health
conditions.
Quality of Life trials (or Supportive Care trials)
explore ways to improve
comfort and the quality of life for individuals
with a chronic illness
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7. Phase I Phase II Phase III Phase IV
Design
features:
• Single,
ascending
dose tiers
• Unblinded
•
uncontrolled
• Placebo
controlled
comparisons
• active
controlled
comparisons
• well-defined
entry
criteria
Randomized
• Controlled
• 2-3 treatment
arms
• broader
eligibility
criteria
• Uncontrolled
•
observational
Duration Up to 1
month
Several months Several years Ongoing
(following
FDA approval
Populatio
n:
Healthy
volunteers
or
individuals
with the
target
disease
(such as
cancer or
HIV)
Individuals
with target
disease
Individuals with
target disease
Individuals
with
target disease,
as
well as new
age
groups,
genders, etc
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8. Sample
size:
20 to 80 200 to 300 Hundreds to
thousands
Thousands
Example: • Study of a
single dose
of drug X in
normal
subjects
Double-blind
study
evaluating
safety
and efficacy of
drug
X vs. Placebo in
patients with
hypertension
Study of drug X
vs.
Standard
treatment
in hypertension
study
Study of
economic
benefit
of newly
approved
drug X
vs. Standard
treatment
for
hypertensio
n
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11. A population at risk for the disease events is
followed over time for the occurrence of disease
and events.
This study used to estimate how often disease or
life events happen in a certain population.
These are the best method for determining the
incidence and natural history of a condition
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13. STUDYS IS OF TWO TYPES
Prospective
•A Group of people is chosen who do not have the
outcome of interest(for example, myocardial infarction).
• The investigator then measures a variety of Variables
that might be relevant to the Development of the
condition
Retrospective
• These use data already collected for other purposes.
The methodology is the same but the study is
performed.
• Outcome is already developed
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14. Studies carried out from present time to future
Can be tailored to collect specific exposure rate
But long wait for events to occur
Expensive
Prone to high dropout rates
Retrospective
• Look at medical events from past to present
• Information is available immediately
• Difficulty in tracing subjects and doubt on
quality of recorded information
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15. Is a type of observational study that are primarily
used to determine prevalence.
Prevalence equals the number of cases in a
population at a given point in time.
All the measurements on each person are made at
one point in time.
COHORT STUDY CROSS
SECTIONAL
Study group Population at risk Entire
population
Common
measures
Risks and rates Prevalence
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16. The prevalence of a health outcome is simply the
proportion of
individuals with the health outcome in a population
PREVELENCE = CASE/TOTAL POPULATION
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17. An observational study that compares patients who
have a disease or outcome of interest (cases) with
patients who do not have the disease
Or outcome (controls), and looks back
retrospectively to compare how
frequently the exposure to a risk factor is present
in each group
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18. Case control studies are usually retrospective.
In this study the only outcome is presence or
absence of the disease
or whatever criteria was chosen to select the cases.
Aim to identify predictors of an outcome
Permit assessment of the influence of predictors on
outcome via
calculation of an odds ratio
Can only look at one outcome
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19. ADVANTAGE DISADVANTAGE
Efficient- saves time
and energy
Used for rare diseases,
small sample sizes
Can generate
hypothesis for future
study
Susceptible to bias-
recall, reporting
Prone to
methodological errors
Selection of an
appropriate
comparison group may
be difficult
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21. An epidemiological experiment in which subjects in a
population are randomly allocated into groups, usually called
study and control.
Groups, to receive or not receive an experimental preventive
or therapeutic
Patients are randomly assigned to the study all groups that
help in avoiding bias in patient
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22. Comparative
One treatment is directly compared to another to establish
superiority.
Minimizes bias
Randomization minimizes allocation bias and selection
bias
Blinding minimizes performance bias
Minimizes confounding factors
Randomization makes groups comparable according both
known
and unknown factors
Statistical reliability
Statistical test of significance is readily interpretable when
the
study is randomised
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23. Might demand vast samples size, which require more
resources from the investigators
Sometimes allocation of participants may be
predictable and result in selection bias when the
study groups are unmasked Trials are of longer
duration and more expensive.
Results may not always mimic real life treatment
situation (e.g.
Inclusion / exclusion criteria; highly controlled
setting)
Ethical limitations: some research cannot be ethically
performed as an RCT (classically, RCT of the effects
of parachutes on the survival of sky-divers)
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24. • Parallel group trial design
• Cross-over trial design
• Factorial design
• Group allocation
• Adaptive design
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Types of RCT
25. A parallel study is a type of clinical study where
treatment and controls are allocated to different
individuals.
In this two groups of treatments, a and b, are
given so that one
group receives only a while another group receives
only b
STUDY
POPULATIO
N
TREAT
MENT
A
TREAT
MENT B
EVALUATION
OUTCOME
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26. This is unlike a crossover study where at first one
group receives treatment A, followed by treatment
B later, while the other group receives vice versa
Key element of this design is randomization
One treatment group, and one treatment-as-usual
group.
Two active treatment groups. One of the groups
might receive an active comparator (a treatment
that’s known to be effective).
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27. One treatment group, and one treatment-as-usual
group. Two active treatment groups. One of the
groups might receive an active
comparator (a treatment that’s known to be
effective).
However, these studies generally require large
number of patients for the analysis
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28. In these types of studies each patient serves as his
own control. Each patient gets both treatments.
Each patient receive first treatment then washout
time is provided then other treatment is provided
to the same.
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30. Studies involving two or more factors while
randomizing are called factorial.
Factorial design permits researchers to investigate
the joint effect of two or more factors on a
dependent variable.
Used when it is desired to study the influence of a
number of factors on the treatments compared as
well as their interaction with different treatments
factors on a dependent variables l designs
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31. If no interaction, can perform two experiments with
less patients than
performing two separate experiments
Can examine interactions if this is of interest.
Cost: It is possible to evaluate multiple treatments
within the same trial using
fewer patients than individual comparisons
DISADVANTAGE
• Potential for adverse effects
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32. Groups of individuals are considered as sampling
unit and treatment is given to group rather than
indivisual subject .
Allows mass intervention
It requirs more patients than indivisuals design
Necessitaties cluster sampling method
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33. An adaptive design allows modification /adaptation
to trial and /or statistical procedure of ongoing
clinical trials .
Major adaptation of trial and /or statistical
procedure of ongoing trials may results in a totally
different trials that is unable to address the
scientific /medical questions the trial intends to
answer.
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34. A clinical trials in which the particepents are not
assigned by chance to diiferent treatment groups .
Particepents may choose which group they want to
be in,or they may be assigned to the groups by the
researchers.
NON RANDMIZED CONCURRENT CONTROL
STUDIES
NON RANDMIZED HISTORICAL CONTROL
STUDIES
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35. Control group is predetermined (already selection
of patients has done )
Non randmized controlled trials relay on
partiecepent
1.Voluenters to join the study
2.Are geographically close to the study site
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36. Historical controls is external control and it
includes
Patient in consecative series
Patient form the literature
Patient from previous studies
Patient as own control
Concurrent ,non randmised
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37. Sunil d.shewale , sharad n. shinde, vikas g. wawale
“Basis of clinical reserch” first edition , Page no 85-94
Dr. H.P. Tipnis, Dr. Amrita Bajaj,”Clinical
Pharmacy”Thired edition , page no:312-328
Jullia lioyd ,ann raven,” handbook of clinical reserch”
page no 66
David machin ,simon day “Textbook of clinical trials”
page no 74-89
Mann, C.J., 2003. Observational research methods.
Research design II: cohort, cross sectional, and case-
control studies. Emergency medicine journal, 20(1),
pp.54-60.
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