ATI RN
130 Top Epidemiology Multiple Choice Questions and Answers PDF Questions
Question 1 of 5
What type of bias occurs when the measurement of exposure or outcome is influenced by the knowledge of the hypothesis?
Correct Answer: D
Rationale: Observer bias (D) occurs when hypothesis knowledge skews measurement (e.g., biased scoring). A is selection, B is broad, C is recall-specific.
Question 2 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 3 of 5
Which of the following is a strategy to control for confounding in the design phase of a study?
Correct Answer: C
Rationale: Matching (C) controls confounding in design (e.g., age-matching). A and B are analysis, D is bias reduction.
Question 4 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 5 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.