HIV Working Group

Kaitlyn CookDoctoral Student, Department of Biostatistics, Harvard University”Stratified Proportional Hazards Models for Multivariate Interval-Censored Data with Time-Dependent Covariates”ABSTRACT: In clinical trials of infectious disease prevention methods, community-level randomization represents a natural study design choice: it enables researchers to rigorously evaluate interventions that are defined and implemented at a supra-individual level, while also reducing the possibility of treatment contamination between trial arms. However, the outcomes from these studies are necessarily cluster-correlated; in the event that they are only monitored and recorded at intermittent study visits, then the outcomes are also interval-censored. Semiparametric regression analysis of cluster-correlated right-censored data might proceed through specification of a stratified model, in which the baseline time-to-event distribution is permitted to vary in an unstructured manner from community to community. However, extending this model to interval-censored data is non-trivial. Here we present an expectation maximization algorithm that permits semiparametric estimation of stratified proportional hazards models to data that are both clustered and interval censored. We also consider its extensions to settings in which covariates may vary over time due to, for example, a study-mandated treatment switch or a change in national treatment guidelines. Finally, we demonstrate the performance of our method using data from the Botswana Combination Prevention Project, a large cluster-randomized trial of combination HIV prevention strategies. Going forward, starting with the March 13 meeting, this working group will be meeting remotely until further notice. The meeting Zoom ID below is a recurring meeting.Join Zoom meetinghttps://harvard.zoom.us/j/590782134Join by telephone (use either number to dial in)+1 929 436 2866+1 669 900 6833International numbers available: https://harvard.zoom.us/u/abP2bHqh1cOne tap mobile: +19294362866,,590782134# US (New York)Join by SIP conference room systemMeeting ID: 590 782 134590782134@zoomcrc.com