AME Research Methods & Evidence-Based Practice 3 — Questions and Answers
Question 1: Which study design is most appropriate for investigating the prevalence of color vision deficiency among active US commercial pilots?
- Randomized controlled trial
- Case-control study
- Cross-sectional survey (Correct answer)
- Longitudinal cohort study
Correct answer: Cross-sectional survey
Cross-sectional surveys measure disease prevalence at a single point in time, making them ideal for determining how common a condition is in a population.
Question 2: An aeromedical researcher wants to determine whether sleep apnea preceded aviation incidents in accident cases. Which design is most efficient when the outcome is rare?
- Case-control study (Correct answer)
- Prospective cohort study
- Clinical trial
- Cross-sectional study
Correct answer: Case-control study
Case-control studies are most efficient for rare outcomes because they start with cases (those with the outcome) and work backward to identify exposures.
Question 3: In evidence-based aeromedical practice, what does the term 'external validity' refer to?
- Whether a study measures what it intends to measure
- Whether study findings can be generalized to the broader aviation population (Correct answer)
- Whether results are statistically significant
- Whether a peer-reviewed journal published the study
Correct answer: Whether study findings can be generalized to the broader aviation population
External validity (generalizability) refers to how well study results apply to populations and settings beyond the original study.
Question 4: A researcher reports an incidence rate of cardiac events of 2 per 10,000 flight hours. This is an example of which epidemiological measure?
- Prevalence proportion
- Crude mortality rate
- Incidence density rate (Correct answer)
- Case fatality rate
Correct answer: Incidence density rate
Incidence density (rate) measures new events per unit of person-time (here, flight hours), not per fixed population count.
Question 5: When an AME applies evidence-based practice, which step follows the formulation of a clinical question (PICO)?
- Critically appraising the evidence
- Applying findings to the patient
- Searching the literature for relevant evidence (Correct answer)
- Evaluating the outcome of applying evidence
Correct answer: Searching the literature for relevant evidence
The EBP process: formulate PICO question → search literature → critically appraise → apply to patient → evaluate outcome.
Question 6: What does a funnel plot asymmetry in a meta-analysis of aeromedical studies most likely indicate?
- Heterogeneity among study populations
- Publication bias (Correct answer)
- Measurement error
- Confounding by indication
Correct answer: Publication bias
Asymmetry in a funnel plot suggests publication bias, meaning smaller studies with negative results may not have been published.
Question 7: In a cohort study following pilots over 10 years, which measure quantifies the association between hypertension and incapacitation events?
- Odds ratio
- Relative risk (risk ratio) (Correct answer)
- Number needed to harm
- Attributable fraction
Correct answer: Relative risk (risk ratio)
Relative risk (risk ratio) is the appropriate measure of association for cohort studies because incidence in exposed versus unexposed groups can be directly calculated.
AME Research Methods & Evidence-Based Practice 3
Which study design is most appropriate for investigating the prevalence of color vision deficiency among active US commercial pilots?