Interventional Study

Question 1

What are the main types of intervention study designs?

Answer 1

1. Before and after study 2. Non-randomized controlled trial 3. Randomized controlled trial (RCT) 4. Qualitative studies

Question 2

What are the key steps in a before-and-after study design?

Answer 2

1. Collect data before intervention (Point A) 2. Apply the intervention 3. Collect data after intervention (Point B)

Question 3

What are the main challenges of interpreting results in before-and-after studies?

Answer 3

1. Bias (results due to other systematic differences) 2. Confounding (other factors that changed) 3. Chance

Question 4

What are the two groups involved in a non-randomized controlled trial?

Answer 4

1. Intervention group (receives intervention) 2. Control group (does not receive intervention)

Question 5

What are the challenges in interpreting results of non-randomized studies?

Answer 5

1. Allocation bias 2. Measurement bias 3. Confounding 4. Chance

Question 6

What is the main purpose of randomization in a randomized controlled trial (RCT)?

Answer 6

To reduce systematic allocation bias by evenly distributing known and unknown confounders.

Question 7

What are the key features of a randomized controlled trial (RCT)?

Answer 7

1. Participants are randomly assigned to groups 2. Each group receives different treatments/interventions 3. Outcomes are measured and compared

Question 8

What are the steps in designing an RCT?

Answer 8

1. Define outcome measures (clinical, patient experience, etc.) 2. Randomize participants 3. Administer intervention 4. Follow-up and measure outcomes

Question 9

How can contamination in an RCT be minimized?

Answer 9

By using cluster randomization, where groups (e.g., schools or communities) are randomized instead of individuals.

Question 10

What is allocation concealment, and why is it important?

Answer 10

Ensuring researchers and participants do not know group assignments beforehand; it prevents bias in participant selection and dropouts.

Question 11

What is blinding in RCTs?

Answer 11

Blinding prevents knowledge of group assignments to minimize bias. It can be single (participants), double (participants and researchers), or triple (participants, researchers, and analysts).

Question 12

What is the purpose of intention-to-treat analysis in RCTs?

Answer 12

To account for participants who drop out or do not adhere to the intervention, ensuring results reflect real-world scenarios.

Question 13

What factors influence the required sample size in a study?

Answer 13

1. Expected effect size 2. Level of significance (e.g., p < 0.05) 3. Study power (e.g., 80-90%)

Question 14

What is the main advantage of an RCT over other study designs?

Answer 14

It minimizes bias and balances known and unknown confounders through randomization.

Question 15

What does “chance” mean in interpreting study results?

Answer 15

Random variation or randomness that might explain observed results, rather than the intervention itself.

Question 16

What statistical tools help account for chance in results?

Answer 16

1. Confidence intervals 2. P-values

Question 17

What is the purpose of a control group in an RCT?

Answer 17

To provide a baseline for comparison, ensuring observed effects are due to the intervention.

Question 18

What are common types of bias in intervention studies?

Answer 18

1. Allocation bias 2. Measurement bias 3. Attrition bias

Question 19

What are confounders in a study?

Answer 19

Factors other than the intervention that can influence outcomes (e.g., changes in environment or health policies).

Question 20

How can confounding be minimized in an RCT?

Answer 20

Through randomization, which distributes confounders evenly between groups.