Question

A study was conducted to compare MMR vaccine history in children with autism and children without autism. What kind of study is being done here?

• A. Cross-sectional study
• B. Cohort study
• C. Case-control study
• D. Clinical trial

Hint:

In case-control studies, always identify the groups: cases (with the outcome) and controls (without the outcome).

Answer 1

The Correct Option is C

In this study, children with autism and without autism are compared with respect to their MMR vaccine history. Since the study looks at two groups (cases and controls) based on an outcome (autism), it is a case-control study. This is a retrospective observational study design used to compare subjects with a condition (cases) and those without it (controls), and it is appropriate for studying rare outcomes such as autism in this context. A cross-sectional study looks at data from a population at one point in time, a cohort study follows subjects over time, and a clinical trial involves intervention. Thus, the correct answer is Case-control study (3).