Mark van der Laan

Van der Laan presented his lecture on "History Adjusted Marginal Structural Models: Application in AIDS Research" on September 15 in Snyder Auditorium. He discussed marginal structural models-methods that address confounding in longitudinal data, but do not allow estimation of how treatment effects may change as a result of time-varying covariates. He developed HA-MSM, a generalization of marginal structural models that incorporates time-dependent effect modification. The application of HA-MSM was illustrated with an example of treatment of HIV-infected patients experiencing incomplete viral suppression during antiretroviral therapy. Lack of effective and well-tolerated alternative regimens, coupled with the desire to protect future treatment options, may result in decisions to delay switching therapies for some individuals. HA-MSM allows estimation of how the effect of non-suppressive therapy may differ depending on time-varying covariates and of the identification of a decision rule for switching that is expected to optimize patient outcomes.

The lecture was followed by a question-and-answer session and the presentation of a plaque.

--Grace Wyshak