Introduction to RWD and RWE for decision-making in healthcare

This chapter introduces the principles of comparative effectiveness research. It explains the role and merits of randomized clinical trials and discusses why their implementation may not always be feasible or timely, or may yield insufficient evidence for decision-making when assessing the real-world effectiveness and safety of treatments. Subsequently, the chapter will describe the potential gap between the effect of treatments in controlled conditions versus in everyday practice, referred to as the efficacy-effectiveness gap. It will then discuss the relevance of real-world data (RWD) and real-world evidence (RWE) to address this gap and touch upon some challenges associated with this. Provided that many types of RWD exist, a distinction is made between their respective sources (e.g., electronic healthcare records) and study designs generating RWE (e.g., non-interventional studies). Finally, the aim and outline of the book are summarized.