Center for Real-World Effectiveness and Safety of Therapeutics (CREST)

What is Real-World Evidence?

Much of what we know about the effects of medications and other medical products, such as vaccines and medical devices, comes from pre-approval randomized clinical trials (RCTs). While RCTs provide essential insights into how well a product can work under ideal conditions, they can be logistically or ethically challenging and often fail to reflect real-world outcomes. Patients, clinicians, and policymakers need real-world evidence (RWE) to understand how medical products do work across diverse patient populations and settings, enabling more informed decisions about which products to use, prescribe, or cover. RWE complements, rather than replaces, the knowledge from pre-approval RCTs, enhancing clinical and policy decision-making.