Which Hill criterion requires that the exposure precede the disease in time?

• A. Dose-response
• B. Analogy
• C. Consistency
• D. Temporality

Answer: (D)

The key idea is that to infer causation you must establish the correct time sequence: the exposure must come before the disease. This time order is what temporality demands. Without it, you can’t tell whether the exposure could have caused the disease or whether the disease influenced exposure or outcomes like recall. In Hill’s set of criteria, temporality is the criterion that explicitly requires the exposure to precede disease onset.

Think of a classic example: if smoking exposure occurs before lung cancer develops, that supports a causal link more than if exposure is measured after the cancer is already diagnosed. The other criteria—such as a stronger association with higher exposure (dose-response), findings that replicate across different studies (consistency), or similarities in other contexts (analogy)—help strengthen the case but do not by themselves guarantee that the exposure occurred before disease.