An Introduction to the Fundamentals of Cohort and Case–Control Studies

Limitation of RCT* Complementary Aspect of Cohort and Case-Control Studies Use of a strict study protocol that is often not Usually representative of settings of routine representative of typical care medical care Exclusion of key patient populations, such May focus on vulnerable and under-represented as children, pregnant women, and elderly people populations Limited sample size May include large number of patients, especially if secondary data sources are used, thereby allowing rare events to be detected Short duration May follow patients for long periods of time (e.g., years) Evaluation of irrelevant treatment comparisons May compare several relevant therapies Outcomes measured may not be important May include any outcome that is measurable to the patient (e.g., surrogate end points) within the data source High cost