Question

Matching is not required in which epidemiological study?

• A. Case control study
• B. Cohort study
• C. Case report
• D. Randomized control trial

Hint:

Matching balances two groups, so a study with only a single patient needs none.

Answer 1

The Correct Option is C

Step 1: Ask what matching is for. It exists to balance two groups on confounding variables so that any difference seen can be attributed to the exposure under investigation.

Step 2: This logic only applies when there are two groups to compare. A case report studies just one patient and presents the full clinical picture of a single, often rare, occurrence. With no second group, matching has no role, making the case report the correct choice.

Step 3: Each of the other designs is comparative by nature. Case control studies set cases against controls, cohort studies follow exposed against unexposed, and randomized controlled trials weigh an intervention arm against a control arm. All of them need matching or randomisation to keep the arms comparable.

Step 4: Therefore the only study without a matching requirement is the case report.

\[\boxed{\text{Case report}}\]