title: Augmented generalized estimating equations for improving efficiency and validity of estimation in cluster randomized trials by leveraging cluster-level and individual-level covariates.
abstract: Recent methodological advances in covariate adjustment in randomized clinical trials have used semiparametric theory to improve efficiency of inferences by incorporating baseline covariates; these methods have focused on independent outcomes. We modify one of these approaches, augmentation of standard estimators, for use within cluster randomized trials in which treatments are assigned to groups of individuals, thereby inducing correlation. We demonstrate the potential for imbalance correction and efficiency improvement through consideration of both cluster-level covariates and individual-level covariates. To improve small-sample estimation, we consider several variance adjustments. We evaluate this approach for continuous and binary outcomes through simulation and apply it to data from a cluster randomized trial of a community behavioral intervention related to HIV prevention in Tanzania.
authors.affiliation: Department of Biostatistics, Harvard School of Public Health, Boston, MA, USA. astephen@hsph.harvard.edu
authors.forename: Alisa J
authors.initials: AJ
authors.lastname: Stephens
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Tchetgen Tchetgen
authors.forename: Victor
authors.initials: V
authors.lastname: De Gruttola
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000517:prevention & control; D000293:Adolescent; D001521:Behavior Therapy / Q000379:methods; D002648:Child; D016000:Cluster Analysis; D003198:Computer Simulation; D003627:Data Interpretation, Statistical; D006801:Humans; D015233:Models, Statistical; D016032:Randomized Controlled Trials as Topic / Q000379:methods*