title: A Bayesian Analysis of a Randomized Clinical Trial Comparing Antimetabolite Therapies for Non-Infectious Uveitis.
abstract: To conduct a Bayesian analysis of a randomized clinical trial (RCT) for non-infectious uveitis using expert opinion as a subjective prior belief.
  
  
  
  A RCT was conducted to determine which antimetabolite, methotrexate or mycophenolate mofetil, is more effective as an initial corticosteroid-sparing agent for the treatment of intermediate, posterior, and pan-uveitis. Before the release of trial results, expert opinion on the relative effectiveness of these two medications was collected via online survey. Members of the American Uveitis Society executive committee were invited to provide an estimate for the relative decrease in efficacy with a 95% credible interval (CrI). A prior probability distribution was created from experts' estimates. A Bayesian analysis was performed using the constructed expert prior probability distribution and the trial's primary outcome.
  
  
  
  A total of 11 of the 12 invited uveitis specialists provided estimates. Eight of 11 experts (73%) believed mycophenolate mofetil is more effective. The group prior belief was that the odds of treatment success for patients taking mycophenolate mofetil were 1.4-fold the odds of those taking methotrexate (95% CrI 0.03-45.0). The odds of treatment success with mycophenolate mofetil compared to methotrexate was 0.4 from the RCT (95% confidence interval 0.1-1.2) and 0.7 (95% CrI 0.2-1.7) from the Bayesian analysis.
  
  
  
  A Bayesian analysis combining expert belief with the trial's result did not indicate preference for one drug. However, the wide credible interval leaves open the possibility of a substantial treatment effect. This suggests clinical equipoise necessary to allow a larger, more definitive RCT.
authors.affiliation: a F. I. Proctor Foundation, University of California, San Francisco , San Francisco , CA , USA.
authors.forename: Erica N
authors.initials: EN
authors.lastname: Browne
authors.affiliation: b Aravind Eye Care System , Madurai , India.
authors.forename: Sivakumar R
authors.initials: SR
authors.lastname: Rathinam
authors.affiliation: c Aravind Eye Care System , Coimbatore , India.
authors.forename: Anuradha
authors.initials: A
authors.lastname: Kanakath
authors.affiliation: b Aravind Eye Care System , Madurai , India.
authors.forename: Radhika
authors.initials: R
authors.lastname: Thundikandy
authors.affiliation: c Aravind Eye Care System , Coimbatore , India.
authors.forename: Manohar
authors.initials: M
authors.lastname: Babu
authors.affiliation: a F. I. Proctor Foundation, University of California, San Francisco , San Francisco , CA , USA.|d Department of Ophthalmology , University of California , San Francisco, San Francisco , CA , USA.|e Department of Epidemiology and Biostatistics , University of California , San Francisco, San Francisco , CA , USA.|f Institute for Global Health, University of California, San Francisco , San Francisco , CA , USA.
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Lietman
authors.affiliation: a F. I. Proctor Foundation, University of California, San Francisco , San Francisco , CA , USA.|d Department of Ophthalmology , University of California , San Francisco, San Francisco , CA , USA.|e Department of Epidemiology and Biostatistics , University of California , San Francisco, San Francisco , CA , USA.
authors.forename: Nisha R
authors.initials: NR
authors.lastname: Acharya
mesh_terms: D000293:Adolescent; D000328:Adult; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use*; D000963:Antimetabolites / Q000627:therapeutic use*; D001499:Bayes Theorem; D005260:Female; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use*; D008297:Male; D008727:Methotrexate / Q000627:therapeutic use*; D009173:Mycophenolic Acid / Q000627:therapeutic use*; D014605:Uveitis / Q000188:drug therapy*; D055815:Young Adult
chemical_list: D000893:Anti-Inflammatory Agents; D000963:Antimetabolites; D007166:Immunosuppressive Agents; D009173:Mycophenolic Acid; D008727:Methotrexate
keywords: Antimetabolite; Bayesian; clinical trial; non-infectious uveitis; statistics