HIV-CAUSAL Collaboration


The HIV-CAUSAL Collaboration is a multinational collaboration of prospective studies of HIV-infected individuals from six European countries and the United States. Originally HIV-CAUSAL was an acronym for HIV Cohorts Analyzed Using Structural Approaches to Longitudinal data.

The collaboration aims at answering three main questions: when to start antiretroviral therapy, what antiretroviral regime to use initially, and when to switch to another regime. These questions are unlikely to be answered by a single study and thus the need for a collaborative project. The HIV-CAUSAL Collaboration pools data collected for clinical purposes within health care systems with few barriers to access in the populations they serve.

The data are analyzed by using methods specifically designed for causal inference from complex longitudinal data, including inverse probability weighting of marginal structural models, g-estimation of structural nested models, and the parametric g-formula.

The HIV-CAUSAL Collaboration is designed to inform evidence-based guidelines and the planning of clinical trials. In addition, the collaboration facilitates understanding and training in causal modeling across leading HIV observational research groups in the United States and Europe.


Grant R01 AI102634, National Institute of Allergy and Infectious Diseases, National Institutes of Health.

Miguel Hernán, Principal Investigator
Rosemary McKaig, Program Officer