STP Research Methods 5 — Questions and Answers
Question 1: Which of the following best describes the intention-to-treat (ITT) principle in an RCT?
- Participants are analyzed according to the treatment they actually received
- All randomized participants are analyzed in the group they were assigned to, regardless of protocol adherence (Correct answer)
- Only participants who completed the study are included in the analysis
- Participants who crossed over to the other arm are excluded
Correct answer: All randomized participants are analyzed in the group they were assigned to, regardless of protocol adherence
ITT analysis includes all randomized participants in their originally assigned groups, preserving the benefits of randomization and avoiding bias from dropout.
Question 2: Specificity of a diagnostic test is defined as:
- The proportion of diseased individuals correctly testing positive
- The probability that a positive test indicates true disease
- The proportion of non-diseased individuals correctly testing negative (Correct answer)
- The ability to detect small changes in biomarker levels
Correct answer: The proportion of non-diseased individuals correctly testing negative
Specificity is the true negative rate — the proportion of people without the disease who are correctly identified as negative by the test.
Question 3: In research ethics, the principle of beneficence requires that researchers:
- Ensure participants provide informed consent
- Maximize benefits and minimize harms to participants (Correct answer)
- Distribute research benefits and burdens fairly across society
- Respect participants' autonomy in decision-making
Correct answer: Maximize benefits and minimize harms to participants
Beneficence obligates researchers to promote the well-being of participants by maximizing potential benefits and minimizing potential harms.
Question 4: A forest plot in a meta-analysis displays:
- The distribution of p-values across included studies
- Effect estimates and confidence intervals for individual studies and a pooled summary (Correct answer)
- The funnel plot symmetry for publication bias detection
- The chronological order of study publication
Correct answer: Effect estimates and confidence intervals for individual studies and a pooled summary
A forest plot shows each study's effect estimate and confidence interval as horizontal lines, with a diamond representing the pooled meta-analytic estimate.
Question 5: Which of the following is an example of information bias in a case-control study?
- Cases and controls are recruited from different populations
- Cases recall past exposures more vividly than controls (recall bias) (Correct answer)
- More cases than controls drop out before data collection
- The exposure and outcome are both measured at the same point in time
Correct answer: Cases recall past exposures more vividly than controls (recall bias)
Recall bias is a form of information bias where cases, motivated by their disease, recall past exposures differently than controls, distorting exposure estimates.
Question 6: In laboratory research, a positive control is used to:
- Confirm that the assay is working correctly and capable of detecting a true positive result (Correct answer)
- Establish a baseline measurement in the absence of any treatment
- Verify that contamination has not occurred in negative samples
- Standardize the concentration of the test substance
Correct answer: Confirm that the assay is working correctly and capable of detecting a true positive result
A positive control contains a known positive result and confirms that the experimental assay is functioning correctly and can detect the expected signal.
Question 7: Triangulation in qualitative research refers to:
- Using three statistical tests to confirm a finding
- Using multiple data sources, methods, or researchers to enhance credibility (Correct answer)
- Selecting three representative participants for in-depth interviews
- Dividing themes into three hierarchical levels
Correct answer: Using multiple data sources, methods, or researchers to enhance credibility
Triangulation uses multiple sources of data, methods, investigators, or theoretical frameworks to cross-verify findings and strengthen the credibility of qualitative research.
STP Research Methods 5
Which of the following best describes the intention-to-treat (ITT) principle in an RCT?