Steps in conducting a RCT 1. Drawing up a protocol 2. Selecting Reference & Experimental population 3. Randomization 4. Manipulation or Intervention 5. Follow up 6. Assessment of outcome 1. Drawing up a protocol Aims and objectives of the study Questions to be answered Criteria for the selection of study and control groups Size of the sample & allocation of subjects in both groups Treatment to be applied - when, where, how Standardization of working procedures and Schedules as well as responsibilities of persons involved in the trial up to the stage of evaluation of outcome of the study. 2. Selecting Reference and Experimental Populations Reference or target population - Population to which the findings of the trial, if found successful, are expected to be applicable (Eg: drugs, vaccines, etc.)  Experimental or Study population Derived from the Reference population Has same characteristics as the Reference population Actual population that participates in the experimental study Must give informed consent - Should be qualified or eligible for the trial 3. Randomization Heart of the control trial Procedure: Participants are allocated into study and control groups Eliminates bias and allows comparability By random allocation every individual gets an equal chance for being allocated in to either groups. 4. Manipulation/ Intervention Having formed the study and control group, the next step is to intervene or manipulate the study (experimental) group by deliberate application or withdrawal or reduction of a suspected causal factor Eg: Drug, Vaccine, Dietary component, a habit 5. Follow up Implies examination of the experimental and control group subjects at defined intervals of time in a standard manner, with equal intensity, under the same given circumstances in the same time frame till final assessment of outcome. Attrition: Inevitable losses to follow up (death, migration, loss of interest) 6. Assessment a. Positive results: Reduced incidence or severity of disease Reduced cost to health service Appropriate outcome in the study b. Negative results: Increased severity or frequency of side effects Complications Deaths BIAS: Any systematic error in the determination of association and outcome. Bias may arise from errors of assessment of outcome due to human element Subjective bias Observer bias Evaluation bias 1. Subjective Bias: Participants, subjectively feel better or report improvement if they knew they were receiving a new form of treatment. This is known as “Subject variation”. 2. Observer Bias: Investigator measuring the outcome of a therapeutic trial may be influenced if he knows beforehand the particular procedure or therapy to which the patient has been subjected. 3. Evaluation Bias: Investigator may subconsciously give a favorable report of the outcome of the trial. Blinding: 1. Single Blind Trial: Participant 2. Double Blind: Partcipant + Investigator 3. Triple Blind: Participant + Investigator + Data Analyzer

2. STEPS IN CONDUCTING A
RANDOMIZED CONTROL TRIAL
By
Dr. LASYA

3. • A study design that randomly assigns participants into an experimental
group or control group.
• Experimental study or Intervention study
• An epidemiological experiment to evaluate new preventive or
therapeutic regimens.
• Gold standard among epidemiological studies in terms of validity.
RANDOMIZED CONTROLLED TRIAL

4. Types of experimental studies
A) Randomized controlled trials
Those involving a process of random allocation
B) Non-randomized or “Non-experimental” trials or Quazi
Experiment
Those departing from strict randomization for practical
purposes, but in such a manner that non-randomization does
not seriously affect the theoretical basis of conclusions

5. 1) Drawing up a protocol
2) Selecting Reference & Experimental population
3) Randomization
4) Manipulation or Intervention
5) Follow up
6) Assessment of outcome
STEPS IN CONDUCTING A RCT

6. 1. Drawing up a protocol
• Aims and objectives of the study
• Questions to be answered
• Criteria for the selection of study and control groups
• Size of the sample & allocation of subjects in both groups
• Treatment to be applied – when, where, how
• Standardization of working procedures and
• Schedules as well as responsibilities of persons involved in the trial up
to the stage of evaluation of outcome of the study.

7. Reference or target population - Population
to which the findings of the trial, if found
successful, are expected to be applicable (Eg:
drugs, vaccines, etc.)
2. Selecting Reference and Experimental Populations

8. Experimental or Study population
• Derived from the Reference population
• Has same characteristics as the Reference population
• Actual population that participates in the experimental study
• Must give informed consent - Should be qualified or eligible for the
trial
Eg:
• Effectiveness of drug in treating anemia – subjects should be anemic
• Effectiveness of a vaccine against a disease – subjects should not be
already immune

9. • Heart of the control trial
Procedure:
• Participants are allocated into study and control groups
• Eliminates bias and allows comparability
• By random allocation every individual gets an equal chance for being
allocated in to either groups.
3. Randomization

10. The critical element of randomization is the unpredictability
of the next assignment

11. • Having formed the study and control group, the next step
is to intervene or manipulate the study (experimental)
group by deliberate application or withdrawal or reduction
of a suspected causal factor
Eg: Drug, Vaccine, Dietary component, a habit
4. Manipulation/ Intervention

12. • Implies examination of the experimental and control group
subjects at defined intervals of time in a standard manner,
with equal intensity, under the same given circumstances in
the same time frame till final assessment of outcome.
Attrition:
• Inevitable losses to follow up (death, migration, loss of
interest)
5. Follow up

13. a) Positive results:
• Reduced incidence or severity of disease
• Reduced cost to health service
• Appropriate outcome in the study
b) Negative results:
• Increased severity or frequency of side effects
• Complications
• Deaths
6. Assessment

14. DESIGN OFA RANDOMISED CONTROL TRIAL
Select suitable population (Reference or Target Population)
Select suitable sample (Experimental or Study Population)
Randomization
Experimental Group Control Group
Manipulation and Follow - up
Assessment

15. BIAS
• Any systematic error in the determination of association and outcome.
• Bias may arise from errors of assessment of outcome due to human element
1. Subjective bias
2. Observer bias
3. Evaluation bias

16. Subjective Bias
• Participants, subjectively feel better or report improvement if
they knew they were receiving a new form of treatment. This is
known as “Subject variation”.

17. Observer Bias
• Investigator measuring the outcome of a therapeutic trial may be
influenced if he knows beforehand the particular procedure or
therapy to which the patient has been subjected.
Evaluation Bias
• Investigator may subconsciously give a favorable report of the
outcome of the trial.

18. BLINDING/ MASKING
(A) Single Blind Trial: The trial is so planned that the participant is not
aware whether he belongs to the study group or control group [Participant]
(B) Double Blind Trial: The trial is planned that neither the doctor nor the
participant is aware of the group allocation and the treatment received.
[Participant + Investigator]

19. (C) Triple Blind Trial: This goes one step further. The
participant, the investigator and the person analyzing the data are a
"blind".
[Participant + Investigator + Data Analyzer]

20. Attrition
Heart of the trial
Quazi Experimental
Masking
Double Blind trial
Randomization
Participant + Investigator
Loss to follow-up
Non – Randomized trial
Blinding
Match the following