Design of the Stress Incontinence Surgical Treatment Efficacy Trial (SISTER)

Objectives. To describe the methods and rationale for the first randomized controlled trial conducted by the Urinary Incontinence Treatment Network. Methods. The primary objective of this clinical trial is to compare two commonly performed surgical procedures for stress urinary incontinence-the Burch colposuspension and the autologous rectus fascial sling-for overall treatment success for urinary incontinence and stress-type symptoms of incontinence at 24 months after surgery. Secondary aims include a comparison of complications, quality of life, sexual function, patient satisfaction, costs, and the need for additional treatments or surgery; and an evaluation of the prognostic value of preoperative urodynamic studies. The Stress Incontinence Surgical Treatment Efficacy Trial is being conducted on 655 women with predominant stress urinary incontinence, as determined by history and physical examination, urinary stress test with witnessed leakage, and voiding diary. Administration of all questionnaires and performance of examinations, tests, and both surgical procedures are standardized within and across the clinical centers. Assessments occur preoperatively and at 6 weeks and 3, 6, 12, 18, and 24 months postoperatively. A sample of 655 women ensures 80% power to detect a 12% difference (60% versus 72%) at the 5% significance level. The intent-to-treat analysis will use Fisher's exact test and time-to-failure analyses. Results. Enrollment was completed in June 2004 with 24 months of follow-up to end in June 2006. Conclusions. This is the first large, multicenter randomized clinical trial comparing these two standard-of-care procedures for stress incontinence.