Abstract
Since the first decentralized clinical trial (DCT) was conducted in 2011, there has been an increased usage of DCT due to its benefits of patient-centricity and generalizability of findings. This trend was further expedited by the global COVID-19 pandemic. We identified 23 case studies across various therapeutic areas and grouped them into different categories according to their purposes-by necessity, for operational benefits, to address unique research questions, to validate innovative digital endpoints, or to validate decentralization as a clinical research platform. We leveraged the estimand framework from ICH E9(R1) including its five attributes (population, treatment, variable, intercurrent event, and summary measure) to critically assess their design and conduct. Common trends, opportunities, and challenges were reported along with recommendations for future DCT. Of note, intercurrent events and associated handling strategies are largely not present when reporting DCT. This is an area that can impact study conclusions and require more dedicated efforts when designing new DCTs.