On statistical analysis for placebo-challenging designs in clinical trials

In clinical trials, appropriate designs are often chosen to address scienti fic/medical questions of particular interest to the investigator. For a cho sen statistical design, however, standard statistical procedures may not be applicable owing to the nature of the design. In this paper we examine sta tistical methods for analysis of data collected from a placebo-challenging design which is often considered for assessment of the efficacy of drug pro ducts for indication of erectile dysfunction. An example concerning a clini cal trial conducted with 120 male patients with erectile dysfunction is use d to illustrate the derived statistical methods, Some recommendations to th e randomization procedure for the study design of this kind are also made. Copyright (C) 2000 John Wiley & Sons, Ltd.