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.
Yang W, Propert KJ, Richard Landis J. Are you the author?
Department of Biostatistics and Epidemiology, Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, U.S.A.
Reference: Stat Med. 2012 Dec 10. Epub ahead of print.