Assessing time-varying causal effect moderation in the presence of cluster-level treatment effect heterogeneity and interference

Biometrika. 2023 Sep;110(3):645-662. doi: 10.1093/biomet/asac065. Epub 2022 Nov 24.ABSTRACTThe micro-randomized trial (MRT) is a sequential randomized experimental design to empirically evaluate the effectiveness of mobile health (mHealth) intervention components that may be delivered at hundreds or thousands of decision points. MRTs have motivated a new class of causal estimands, termed "causal excursion effects", for which semiparametric inference can be conducted via a weighted, centered least squares criterion (Boruvka et al., 2018). Existing methods assume between-subject independence and non-interference. Deviations from these assumptions often occur. In this paper, causal excursion effects are revisited under potential cluster-level treatment effect heterogeneity and interference, where the treatment effect of interest may depend on cluster-level moderators. Utility of the proposed methods is shown by analyzing data from a multi-institution cohort of first year medical residents in the United States.PMID:37711671 | PMC:PMC10501736 | DOI:10.1093/biomet/asac065
Source: Biometrika - Category: Biotechnology Authors: Source Type: research