Crossover studies

A randomized crossover study is designed to have a subject undergo a sequence of different treatments. This provides the advantage of decreasing confounding, as each subject will work as their own control. These provide research works and efficient ways to simultaneously compare an intervention. In Urology, this study design has been implemented in the evaluation of new technologies for the treatment of benign prostatic hyperplasia. This study design is suitable for short interventions that allow subjects in the control group to proceed with active treatment in a timely fashion. The pivotal trials for Rezum, a minimally invasive surgical therapy for benign prostatic hyperplasia is an excellent example of this study design. Enrolled subjects were randomized to active treatment (Rezum) versus sham/control procedure. After analyzing symptom improvement and changes in International Prostate Symptom Scores, subjects in the control group crossed over to active treatment, replicating the results of the initial active treatment arm.