title: Assessing the effectiveness of antiretroviral adherence interventions. Using marginal structural models to replicate the findings of randomized controlled trials.
abstract: Randomized controlled trials of interventions to improve adherence to antiretroviral medications are not always feasible. Marginal structural models (MSM) are a statistical methodology that aims to replicate the findings of randomized controlled trials using observational data. Under the assumption of no unmeasured confounders, 3 MSM estimators are available to estimate the causal effect of an intervention. Two of these estimators, G-computation and inverse probability of treatment weighted (IPTW), can be implemented using standard software. G-computation relies on fitting a multivariable regression of adherence on the intervention and confounders. Thus, it is related to the standard multivariable regression approach to estimating causal effects. In contrast, IPTW relies on fitting a multivariable logistic regression of the intervention on confounders. This article reviews the implementation of these methods, the assumptions underlying them, and interpretation of results. Findings are illustrated with a theoretic data example in which MSM are used to estimate the effect of a behavioral intervention on adherence to antiretroviral therapy.
authors.affiliation: Division of Biostatistics, University of California at Berkeley, Berkeley, CA 94720-7360, USA. mayaliv@berkeley.edu
authors.forename: Maya L
authors.initials: ML
authors.lastname: Petersen
authors.forename: Yue
authors.initials: Y
authors.lastname: Wang
authors.forename: Mark J
authors.initials: MJ
authors.lastname: van der Laan
authors.forename: David R
authors.initials: DR
authors.lastname: Bangsberg
mesh_terms: D019380:Anti-HIV Agents / Q000008:administration & dosage* / Q000627:therapeutic use*; D015658:HIV Infections / Q000188:drug therapy*; D006801:Humans; D010349:Patient Compliance; D010353:Patient Education as Topic / Q000458:organization & administration; D010595:Pharmacists; D016032:Randomized Controlled Trials as Topic / Q000379:methods*; D016896:Treatment Outcome
chemical_list: D019380:Anti-HIV Agents