NBCE Research and Development 2 — Questions and Answers
Question 1: A researcher wants to determine whether a new chiropractic technique reduces neck pain more than standard care. Which study design is most appropriate?
- Case series
- Randomized controlled trial (Correct answer)
- Cross-sectional survey
- Ecological study
Correct answer: Randomized controlled trial
A randomized controlled trial is the gold standard for comparing treatment efficacy between two interventions.
Question 2: In a clinical study, the Hawthorne effect refers to:
- Placebo response confounding treatment outcomes
- Subjects changing behavior because they know they are being observed (Correct answer)
- Regression to the mean over repeated measurements
- Selection bias introduced by non-random sampling
Correct answer: Subjects changing behavior because they know they are being observed
The Hawthorne effect occurs when participants alter their behavior simply due to awareness of being studied.
Question 3: Which statistical measure describes the probability that a diagnostic test will correctly identify a patient without the condition as negative?
- Sensitivity
- Positive predictive value
- Specificity (Correct answer)
- Likelihood ratio
Correct answer: Specificity
Specificity is the proportion of true negatives correctly identified by a test (TN / TN + FP).
Question 4: A Type II error in hypothesis testing occurs when a researcher:
- Rejects a true null hypothesis
- Fails to reject a false null hypothesis (Correct answer)
- Uses an inappropriate statistical test
- Over-adjusts for multiple comparisons
Correct answer: Fails to reject a false null hypothesis
A Type II (beta) error is a false negative — failing to detect a real effect that truly exists.
Question 5: Which level of evidence is HIGHEST in the evidence hierarchy for evaluating chiropractic interventions?
- Expert opinion
- Well-designed cohort study
- Systematic review with meta-analysis of RCTs (Correct answer)
- Single randomized controlled trial
Correct answer: Systematic review with meta-analysis of RCTs
Systematic reviews and meta-analyses of multiple RCTs represent the highest level of clinical evidence.
Question 6: In research ethics, the principle of beneficence requires that investigators:
- Ensure equal distribution of research burdens across populations
- Respect each participant's autonomy and right to self-determination
- Maximize benefits and minimize harms to research subjects (Correct answer)
- Obtain voluntary and informed consent from all participants
Correct answer: Maximize benefits and minimize harms to research subjects
Beneficence obligates researchers to promote the well-being of participants and minimize risks.
Question 7: An odds ratio of 1.0 in a case-control study indicates:
- Strong positive association between exposure and disease
- The exposed group has twice the disease risk
- No association between the exposure and the outcome (Correct answer)
- Statistical significance at p < 0.05
Correct answer: No association between the exposure and the outcome
An odds ratio of 1.0 means the odds of the outcome are equal in both exposed and unexposed groups, indicating no association.
NBCE Research and Development 2
A researcher wants to determine whether a new chiropractic technique reduces neck pain more than standard care.
Which study design is most appropriate?