Harm and Causation: Assessing the Value of Studies of Harm
Harm and causation is a critical topic in evidence-based medicine. Harm questions come up frequently in clinical care as much harm data is shared in the lay press. “Does this food/chemical/environmental exposure cause that disease?” is a very common concern for patients and families. This chapter includes teaching the foundational concepts of confounding variables, association vs. causation, and odds ratios as compared to risk ratios. An understanding of the limitations of cohort studies in answering questions of causation can be useful before moving on to therapy and randomized controlled trials, because it is the confounding bias that is addressed by randomization. It is also a good time to teach about the value of cohort studies in uncovering population-wide impacts of harms that cannot be feasibly studied in randomized trials.
