Real-world data: bridging the gap between clinical trials and practice.

Real-world data (RWD) are rapidly emerging sources of information for patients, clinicians and regulators. While randomized controlled trials (RCTs) reduce bias and confounding through the randomization process and provide the highest quality of evidence regarding drug efficacy, RCTs may be impractical or unfeasible for rare diseases or disease subsets. And yet, studies attempting to replicate clinical trial results using observational datasets have failed. Given the inherent differences between observational data and clinical trial results, this discordance is not surprising. However, RWD may still have independent value as complementary tools to trial results. In this viewpoint, we explore the challenges of RWD and discuss key questions that clinicians, patients, and regulators will need to consider when faced with positive efficacy data from clinical trials, and negative effectiveness data from real world studies. Finally, we explore novel trial designs that might help bridge the gap from RCTs to RWD.