title: A survey of physician efficacy requirements to plan clinical trials.
abstract: OBJECTIVE
  Eliciting physician efficacy requirements for utilizing medical treatments can be a useful means of helping plan a clinical trial. Efficacy requirements were studied for female stress urinary incontinence, where an experimental treatment (collagen injection) was compared to the standard therapy (surgery).
  
  
  METHODS
  A self-administered questionnaire was sent to 223 North American urologists, gynecologists, and urogynecologists. An interviewer also administered a similar questionnaire to 20 other clinician-specialists.
  
  
  RESULTS
  The response rate for the self-administered questionnaire was 48.4% (108/223). All 20 clinician-specialists who were approached for an interview consented. On average, respondents to the self-administered questionnaire indicated they would consider using collagen as the first line treatment if the absolute reduction in efficacy of collagen versus surgery was no larger than 23%. The corresponding result for the interview-questionnaire was 22%. Efficacy was measured as patient satisfaction with treatment. In the opinion of the physicians, surgery would remain the standard therapy if the reduction was greater than 34% (self-administered questionnaire), or 37% (interviewer-administered questionnaire).
  
  
  CONCLUSIONS
  The elicitation of physician efficacy requirements provides an idea of the treatment effect that would be needed for a clinical trial to have an impact on medical practice. These requirements can be used to calculate a relevant sample size.
authors.affiliation: Centre for Clinical Epidemiology and Community Studies, S.M.B.D. Jewish General Hospital, Joint Departments of Epidemiology and Biostatistics and Occupational Health, McGill University, Montreal, Canada. mark.oremus@mail.mcgill.ca
authors.forename: Mark
authors.initials: M
authors.lastname: Oremus
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Collet
authors.forename: Jacques
authors.initials: J
authors.lastname: Corcos
authors.forename: Stanley H
authors.initials: SH
authors.lastname: Shapiro
mesh_terms: D002986:Clinical Trials as Topic; D003094:Collagen / Q000627:therapeutic use; D005260:Female; D006801:Humans; D010820:Physicians / Q000706:statistics & numerical data*; D012107:Research Design / Q000706:statistics & numerical data*; D011795:Surveys and Questionnaires; D016896:Treatment Outcome; D014550:Urinary Incontinence, Stress / Q000601:surgery / Q000628:therapy
chemical_list: D003094:Collagen