Opportunities and challenges of clinical research in the big-data era: from RCT to BCT

At the current stage, the main types of clinical research include prospective study, retrospective study, translational research, and evidence-based study, whilethe prospective randomized controlled trial (RCT) remains the dominating research type (Figure 1). In a typical RCT, the researchers randomly divide the subjects into several groupsprovided with different interventions, and then compare the results. With a sufficient number of subjects recruited, RCTs can ensure that all the known and unknown confounding factors have the same effects on each group.