Adaptive designs for clinical trials

Abstract

The gold standard for interventional studies is the randomized controlled trial (RCT). The RCT follows a linear path with prespecified plans and a little option for flexibility within its implementation. The RCT is also resource and time-intensive and can be a limitation in epidemics or pandemics where more rapid responses can reduce adverse effects. Adaptive designs (ADs) allow for continuous evidence-based modifications to key elements of trial design even as data collection is going on. Reduced use of resources, reduced time to complete the trial, flexibility in the allocation of participants to study arms and improved likelihood for scientifically valid trial results are added advantages with AD. ADs can be applied from early-phase trials to confirmatory trials. In this paper, we introduce key aspects of AD that Ophthalmologists can apply to clinical trials in Ophthalmology. We briefly introduce the rationale for AD, commonly used terminology, and design elements.