Randomized, observational, interventional, and real-world—What's in a name?

摘要

Epidemiologic study designs are the focus of renewed interest in the current era of real-world evidence (RWE). Described with terms including case-control or cohort studies, observational designs were developed mainly to assess causes and correlates of human disease, but in recent decades, such methods have been used more frequently to evaluate the effects of medical products when used in routine clinical care (ie, not assigned by a research protocol), often with a focus on drug safety. Over the same time period, randomized controlled trials (RCTs) have become the archetype for experimental approaches (ie, protocol-assigned interventions). A dichotomy of randomized trials vs observational studies arose and was subsequently emphasized, related especially to the emergence of evidence-based medicine, with RCTs considered the benchmark of study designs—including for regulatory decisions that require adequate and well-controlled studies as the basis for substantial evidence in support of the effectiveness of new drugs.