Abstract

The randomized controlled trial (RCT) is widely regarded as a key approach to assessing the efficacy and safety of new medical treatments. RCTs are near the top of the evidence-based medicine hierarchy, and the results of well designed and carefully conducted RCTs influence physicians, drugs regulators, and health policy-makers (Sackett et al. 1996). In an RCT, patients with a medical illness are allocated by chance to one of two or more study arms or “conditions.” Patients allocated to the experimental condition receive the new treatment under investigation, while patients allocated to the control condition receive a standard treatment to which the new treatment is being compared. All patients are followed for a defined period of time, and information on prespecified outcome measures is collected. Physician-researchers conclude that the new treatment is effective if patients in the experimental condition outperform those in the control condition in the primary outcome measure according to statistical tests of significance.