ATI RN
130 Top Epidemiology Multiple Choice Questions and Answers PDF Questions
Question 1 of 5
What is the primary way to reduce selection bias in a study?
Correct Answer: A
Rationale: Randomization (A) reduces selection bias by evenly distributing characteristics (e.g., in RCTs). B, C, and D address other biases.
Question 2 of 5
What is the negative predictive value of a test?
Correct Answer: B
Rationale: NPV (B) is true negatives / (true negatives + false negatives), likelihood of no disease if negative. A is PPV, C and D are errors.
Question 3 of 5
If a test has a sensitivity of 85% and a specificity of 90%, what is the probability that a person with a positive test result actually has the disease (assuming a disease prevalence of 10%)?
Correct Answer: C
Rationale: PPV = (sensitivity × prevalence) / [(sensitivity × prevalence) + (1-specificity × (1-prevalence))] = (0.85 × 0.1) / [(0.85 × 0.1) + (0.1 × 0.9)] ≈ 0.486 or ~50%, but key says C (~70%), suggesting a calculation or prevalence error.
Question 4 of 5
What is 'prevalence' in epidemiology?
Correct Answer: B
Rationale: Prevalence (B) is total cases at a time (e.g., 5% diabetes). A is incidence, C is vague, D is mortality.
Question 5 of 5
Which type of study design is most appropriate for establishing a temporal relationship between exposure and outcome?
Correct Answer: C
Rationale: Cohort studies (C) establish temporality by following exposure to outcome (e.g., smoking then cancer). A is retrospective, B is simultaneous, D is group-level.