Canadian Health Information Management Association Practice Exam

In a case-control study, why are cases and controls typically matched on variables like age and sex?

1. So that cases and controls are similar except for the disease and health characteristic under study

2. So that cases and controls are similar except for the disease under study only

3. So that cases and controls are similar except for the health characteristic only

4. So that cases and controls are similar for all aspects of the study

The correct answer is: So that cases and controls are similar except for the disease and health characteristic under study

In a case-control study, matching cases and controls on variables such as age and sex is critical to ensure that both groups are comparable in terms of these demographic characteristics. This allows for a more accurate assessment of the relationship between the exposure of interest and the outcome being studied. By controlling for age and sex, researchers can minimize confounding variables that might otherwise skew the results. If cases (individuals with the disease) and controls (individuals without the disease) are systematically different in these respects, it becomes challenging to determine whether observed differences in health characteristics are due to the exposure being studied or other underlying factors related to age or sex. This approach enables the researcher to isolate the impact of the specific disease-related factor being examined, ensuring that any differences observed between cases and controls can be more confidently attributed to that factor rather than to age or sex differences. Thus, the cases and controls remain similar except for the disease and the specific health characteristics under study.