A nurse wanted a screening test that was very sensitive in determining who might have a particular illness. What might be a problem with using such a sensitive test? (Select all that apply.)

Correct Answer: C

Rationale: The problem with very sensitive tests is that the test picks up almost all people with the disease but also many others who do not have the disease. These 'false positives' result in persons needing follow-up diagnostic tests. Additional time, effort, and expense, as well as worry, result until the negative test results are obtained.

Correct Answer: C

Rationale: Case-control studies (C) compare diseased (cases) and non-diseased (controls) to assess past exposures. A measures prevalence, B follows exposure, D tests interventions.

Correct Answer: C

Rationale: Primary prevention (C) prevents disease onset via education/promotion (e.g., vaccination). A is secondary, B is tertiary, D is monitoring.

Correct Answer: D

Rationale: Attrition bias (D) arises from differential loss to follow-up affecting results (e.g., in cohorts). A is selection, B is data error, C is recall.

Correct Answer: B

Rationale: Descriptive studies (B) describe disease patterns (e.g., who, where, when). A and C are analytical, D is clinical.