controlled trial


Health Economics

  • (written as Controlled Trial)
    In trials, one group of subjects (the experimental group or experimental arm) receives an experimental drug, while another group (the control group or control arm) receives the usual treatment for the disease, another treatment of interest, or a placebo. The control group provides a standard against which the experimental observations may be evaluated and minimizes bias. For example, dividing subjects into two groups, the experimental arm and the control arm, means that any selection bias will be present in both arms and thus the danger of inferring an effect where there is in fact none is reduced. Randomization in this way ideally means that both arms are subject to the same external confounding effects, the only difference between them being the active intervention