title: Estimating the efficacy of an interstitial cystitis/painful bladder syndrome medication in a randomized trial with both non-adherence and loss to follow-up.
abstract: We are motivated by a randomized clinical trial evaluating the efficacy of amitriptyline for the treatment of interstitial cystitis and painful bladder syndrome in treatment-naïve patients. In the trial, both the non-adherence rate and the rate of loss to follow-up are fairly high. To estimate the effect of the treatment received on the outcome, we use the generalized structural mean model (GSMM), originally proposed to deal with non-adherence, to adjust for both non-adherence and loss to follow-up. In the model, loss to follow-up is handled by weighting the estimation equations for GSMM with one over the probability of not being lost to follow-up, estimated using a logistic regression model. We re-analyzed the data from the trial and found a possible benefit of amitriptyline when administered at a high-dose level.
authors.affiliation: Department of Biostatistics and Epidemiology, Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, U.S.A.
authors.forename: Wei
authors.initials: W
authors.lastname: Yang
authors.forename: Kathleen J
authors.initials: KJ
authors.lastname: Propert
authors.forename: J Richard
authors.initials: JR
authors.lastname: Landis
mesh_terms: D000639:Amitriptyline / Q000627:therapeutic use; D018712:Analgesics, Non-Narcotic / Q000627:therapeutic use; D003198:Computer Simulation; D018856:Cystitis, Interstitial / Q000150:complications / Q000188:drug therapy; D006801:Humans; D016015:Logistic Models; D059012:Lost to Follow-Up; D015233:Models, Statistical; D010146:Pain / Q000150:complications; D010349:Patient Compliance; D016896:Treatment Outcome
chemical_list: D018712:Analgesics, Non-Narcotic; D000639:Amitriptyline