title: Outcomes following vaginal prolapse repair and mid urethral sling (OPUS) trial--design and methods.
abstract: BACKGROUND
  The primary aims of this trial are to determine whether the use of a concomitant prophylactic anti-incontinence procedure may prevent stress urinary incontinence symptom development in women undergoing vaginal prolapse surgery and to evaluate the cost-effectiveness of this prophylactic approach.
  
  
  OBJECTIVE
  To present the rationale and design of a randomized controlled surgical trial (RCT), the Outcomes following vaginal Prolapse repair and mid Urethral Sling (OPUS) Trial highlighting the challenges in the design and implementation.
  
  
  METHODS
  The challenges of implementing this surgical trial combined with a cost-effectiveness study and patient preference group are discussed including the study design, ethical issues regarding use of sham incision, maintaining the masking of study staff, and pragmatic difficulties encountered in the collection of cost data. The trial is conducted by the NICHD-funded Pelvic Floor Disorders Network.
  
  
  RESULTS
  The ongoing OPUS trial started enrollment in May 2007 with a planned accrual of 350. The use of sham incision was generally well accepted but the collection of cost data using conventional billing forms was found to potentially unmask key study personnel. This necessitated changes in the study forms and planned timing for collection of cost data. To date, the enrollment to the patient preference group has been lower than the limit established by the protocol suggesting a willingness on the part of women to participate in the randomization.
  
  
  CONCLUSIONS
  Given the invasive nature of surgical intervention trials, potential participants may be reluctant to accept random assignment, potentially impacting generalizability.
  
  
  CONCLUSIONS
  Findings from the OPUS trial will provide important information that will help surgeons to better counsel women on the benefits and risks of concomitant prophylactic anti-incontinence procedure at the time of vaginal surgery for prolapse. The implementation of the OPUS trial has necessitated that investigators consider ethical issues up front, remain flexible with regards to data collection and be constantly aware of unanticipated opportunities for unmasking. Future surgical trials should be aware of potential challenges in maintaining masking and collection of cost-related information.
authors.affiliation: Department of Urology, University of Michigan, Ann Arbor, Michigan, USA. jtwei@umich.edu
authors.forename: John
authors.initials: J
authors.lastname: Wei
authors.forename: Ingrid
authors.initials: I
authors.lastname: Nygaard
authors.forename: Holly
authors.initials: H
authors.lastname: Richter
authors.forename: Morton
authors.initials: M
authors.lastname: Brown
authors.forename: Matthew
authors.initials: M
authors.lastname: Barber
authors.lastname: Xiao Xu
authors.forename: Kimberly
authors.initials: K
authors.lastname: Kenton
authors.forename: Charles
authors.initials: C
authors.lastname: Nager
authors.forename: Joseph
authors.initials: J
authors.lastname: Schaffer
authors.forename: Anthony
authors.initials: A
authors.lastname: Visco
authors.forename: Anne
authors.initials: A
authors.lastname: Weber