Another view of active-controlled trials.
Placebo-controlled efficacy trials may become more difficult to carry out with the increasing availability of effective therapies, especially for serious illnesses where denial of effective therapy may be objectionable ethically. Active-controlled trials aimed at establishing efficacy by demonstration of "equivalence" to "standard" therapy have potentially serious interpretational problems, and do not necessarily encourage good experimental practice. This article describes an alternative approach to the analysis of data from active-controlled trials using the information that makes an active-controlled trial necessary or desirable, namely a large, valid body of information about the consequence of using placebo. The approach uses information about placebo responses and also active agent responses from prior placebo-controlled trials to determine the likelihood of a significant active-placebo difference in an active-controlled trial, or in a trial with a vestigial placebo group. The sensitivity of the treatment comparisons depends directly on the quality of the design and execution of the active-controlled trial. The method is illustrated with data from trials of an H2-receptor antagonist in the treatment of acute duodenal ulcer.
Merck, Sharp, and Dohme Research Laboratories, West Point, Pennsylvania 19486.
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D001499:Bayes Theorem; D002986:Clinical Trials as Topic; D004311:Double-Blind Method; D004381:Duodenal Ulcer / Q000188:drug therapy*; D006635:Histamine H2 Antagonists / Q000627:therapeutic use; D006801:Humans; D015201:Meta-Analysis as Topic; D010919:Placebos; D013223:Statistics as Topic; D016896:Treatment Outcome
D006635:Histamine H2 Antagonists; D010919:Placebos