Designing clinical trials in women's health

Although outcomes in women's health are not as spectacular as in conditions like cancer, the large number of women who present each year means that the overall impact of these conditions is enormous. Similarly, although suboptimal therapies may not individually be much worse than best practice, the overall effect on a nation's health, wealth and happiness is substantial. There is a therefore a real need to gather evidence as to which, if any, women, benefit from any particular therapy. Well-designed randomised controlled trials (RCTs) help provide reliable evidence on a treatment's effectiveness. In this article, we consider important aspects of designing a good clinical trial; and in particular their application to women's health issues. Designed as an overview of the subject, we consider how large trials need to be; the choice of endpoints; how they should be analysed; and also more practical considerations in running a successful trial. The considerations given here are of use not only to clinicians or researchers preparing to run their own trial, but also to anyone who reads reports of trials, and should help clinicians make informed judgements about evidence presented in published reports.