title: A comparison of group sequential methods for binary longitudinal data.
abstract: Interim analyses are conducted to allow for early termination of the trial, for ethical as well as economical reasons. Here we consider interim analyses in repeated measurements studies where the measurements are binary. Two methods for analysing this kind of data are compared according to their operating characteristics. A subject-specific approach based on the logistic random-effects model is compared with the population-averaged approach based on the generalized estimating equations. The comparison is illustrated with simulations using a randomized clinical trial for toenail fungal infection.
authors.affiliation: Biostatistical Center, Catholic University of Leuven, U.Z. St.-Rafaël, Kapucijnenvoer 35, B-3000 Leuven, Belgium.
authors.forename: Bart
authors.initials: B
authors.lastname: Spiessens
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Lesaffre
authors.forename: Geert
authors.initials: G
authors.lastname: Verbeke
mesh_terms: D000935:Antifungal Agents / Q000627:therapeutic use; D001530:Belgium; D018849:Controlled Clinical Trials as Topic / Q000941:ethics / Q000706:statistics & numerical data*; D003627:Data Interpretation, Statistical; D005533:Foot Dermatoses / Q000188:drug therapy; D006801:Humans; D016014:Linear Models; D016015:Logistic Models; D008137:Longitudinal Studies; D014009:Onychomycosis / Q000188:drug therapy; D012107:Research Design / Q000706:statistics & numerical data*; D016896:Treatment Outcome
chemical_list: D000935:Antifungal Agents