Match each epidemiological study scenario or flaw with the specific type of bias it best describes.
- Participants in a study alter their behavior (e.g., eat healthier) simply because they are aware they are being monitored by investigators.Hawthorne effect
- Patients with a newly diagnosed illness remember past exposures more thoroughly than healthy control subjects.Recall bias
- A spurious association is found in a case-control study because both the exposure and the disease independently increase the chance of hospital admission.Berkson bias
- Results of a prospective cohort study are skewed because a disproportionate number of subjects drop out over the 10-year follow-up period.Attrition bias
Answer
Scenario 1 matches the Hawthorne effect, Scenario 2 matches Recall bias, Scenario 3 matches Berkson bias, and Scenario 4 matches Attrition bias.
Each scenario describes the classic definition of its corresponding bias. The Hawthorne effect is observation-induced behavior change; recall bias relates to differential memory among cases and controls; Berkson bias is a hospital-admission selection artifact; and attrition bias results from differential loss to follow-up in prospective studies.
Step-by-Step Solution
Key Concept
Identifying and categorizing common types of bias in epidemiological research.