Which is NOT one of Hill's criteria for causation?

• A. Temporality
• B. Dose-response
• C. Randomized controlled trials
• D. Experimental evidence

Answer: (C)

Hill’s criteria are a set of considerations used to judge whether an observed association might be causal, based on how the data behave across different aspects of the relationship. They include temporality (the cause must come before the effect), a dose–response relationship (a biological gradient), and experimental evidence (information from manipulating the exposure). Randomized controlled trials are a powerful study design to test causality, but they aren’t themselves listed as one of Hill’s criteria; rather, they can provide experimental evidence. Hill’s framework also encompasses other factors like strength, consistency, plausibility, coherence, specificity, and analogy. So, while experimental evidence is a criterion, a specific design like a randomized controlled trial is not named as a separate Hill criterion.