Randomized Clinical Trials with Noncompliance: Issues, Definitions and Problems of Commonly Used Analyses

The chapter discusses the randomized clinical trial (RCT) with noncompliance, in which only patients assigned to an experimental treatment group can have access to the experimental treatment, the simple noncompliance RCT. For certain treatments, such as flu vaccine or quitting smoking, it is not ethical to randomly assign high-risk patients to receive either the treatment or the placebo. Thus, to alleviate the ethical concern in application of the traditional RCT, the randomized encouragement design (RED) is often suggested. Based on whether noncompliance can occur in only one or both of the two randomized groups, the randomized consent designs can be classified as a single-consent randomized design (SCRD) and a double-consent randomized design (DCRD). Controlled Vocabulary Terms randomized controlled trial