BASICS OF RCT
Dr. Anil Sharma, PhD(N)
Professor and Principal
Manikaka Topawala
Institute of Nursing-
CHARUSAT, Changa
Accredited Grade “A+” by
NAAC
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Flow of Presentation
 Understand meaning of RCT.
 Illustrate Important features of RCT.
 Evaluate the phases of RCT.
 Take home message
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Types of Quantitative Research Design
1. Experimental Research Design
i. True experimental design/ Randomized Controlled Trial
a. Pre-test post-test control group
b. Post-test only control group
c. Solomon four group
d. Factorial design
e. Randomized block design
f. Crossover design
g. Latin square design
ii. Quasi-experimental research design:
a. Non-randomized control group design
b. Time-series design
iii. Pre-experimental research design:
a. One group pre-test post-test design
b. Once shot case study 3

Randomized Controlled Trial (RCT)
 Gold Standard
 Generating scientific evidences
 Designed to assess clinical intervention.
 Covers three mandatory characteristics of true
experimental design (Manipulation, Randomization and
Control).
 RCT completely balance selection bias by doing
randomization control.
 RCT balance the confounding variables and eliminate the
influence of confounding variable (High Internal Validity)
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Three important characteristic of Randomized
Controlled trial
 Manipulation: Independent variable administration
 Control: Two ways, keeping control group and control over
extraneous variables:
 Matching
 Counter Balancing- all intervention to all participants but flow of
intervention varies.
 Homogeneity by statistical method: By using chi-square test, we
assess no significant difference between two groups
 Randomization:
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THREE PILLARS OF RCT
1. Randomization
2. Allocation concealment
3. Blinding
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Randomization
 Randomly allocating the study participants to one of
intervention group.
For example: Having two groups X & Y
 Generating Random Number Sequence such as
XXYYXYXXXXYXYXXYY
 Computer software
 Random Number tables
 Flipping a coin
 Lottery method
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Why Randomization?
 To handle Selection bias (But not a primary
purpose of it)
 Achieve good Baseline Balance Between Study
Groups with respect to known and unknown
confounders
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Allocation Concealment
Generated allocation sequence and handed over to
Researcher openly
May create Selection Bias
Hence, allocation sequence
should be concealed
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 Blinding or Masking:
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Participants Patients Reporting bias
Investigator Person delivering
intervention
Interviewer bias
Assessor Person assessing the
outcome
Ascertainment
bias
Statistician Person analyzing the
data
Biased reporting
of result

 Blinding or Masking:
 Single blind trial: Participants kept blind about
intervention
 Double blind trial: Participants and the
investigator who administered the intervention
kept blind
 Triple blind trial: Participants, investigator and data
collector (who assess the outcome) kept blind to
eliminate chances of placebo, performance and
measurement bias
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Steps of Randomized Control trial (RCT)
1. Protocol development-Blue print of research study
2. Identification of population: select study population
3. Perform randomization: Core of RCT.
4. Manipulation: Implementation of intervention
5. Follow-up: On defined interval of time to ensure
generalization
6. Assessment: Assessing outcome of study
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Types of Randomized Control trial (RCT)
1. Based on Outcome:
1. Clinical trial
2. Preventive trial
3. Risk factor trial
4. Cessation trial
5. Evaluation trial
2. Based on study Design:
1. Parallel group design
2. Crossover design
3. Factorial design
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Randomized Clinical trial (RCT)
It has four phases:
1. Phase-I: Initial development of drug or therapy (safety, tolerance,
optimal dose)- This is generally a small-scale study with simple
design (Focus on developing best possible treatment)
2. Phase-II: Seeking preliminary evidence of treatment effectiveness.
This phase work as assessing the feasibility of launching rigorous
test. (Work as pilot study)
3. Phase-III: this is real implementation of drug or therapy at large
scale to visualize the efficacy of treatment including the
observation of adverse effects, if any. (Multiple sites identified to
enhance the internal and external validity)
4. Phase-IV: actual assessment of external validity take place.
(Check for effectiveness during widespread use of treatment) 14

If you are planning to do a RCT then make sure to
register your trial at CTRI (Clinical Trial Registry of
India) portal of Government of India
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Any Doubt ?
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Thank You
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