Challenges and lessons learned from Covid-19 trials - should we be doing clinical trials differently?

The COVID-19 crisis led to a flurry of clinical trials activity. The COVID-Evidence database shows 2,814 COVID-19 randomized trials registered as of February 16, 2021. Most were small (only 18% have a planned sample size >500) and the rare completed ones have not provided published results promptly (only 283 trial publications as of 2/2021). Small randomized trials and observational, non-randomized analyses have not had a successful track record and have generated misleading expectations. Different large trials on the same intervention have generally been far more efficient in producing timely and consistent evidence. The rapid generation of evidence and accelerated dissemination of results have led to new challenges for systematic reviews and meta-analyses (e.g. rapid, living, and scoping reviews). Pressure to regulatory agencies has also mounted with massive emergency authorizations, but some of them have had to be revoked. Pandemic circumstances have disrupted the way trials are conducted; therefore, new methods have been developed and adopted more widely to facilitate recruitment, consent, and overall trial conduct. Based on the COVID-19 experience and its challenges, planning of several large, efficient trials, and wider use of adaptive designs may change the future of clinical research. Pragmatism, integration in clinical care, efficient administration, promotion of collaborative structures, and enhanced integration of existing data and facilities may be several of the legacies of COVID-19 on future randomized trials.