SDS Seminar Series – Dr. Emily Roberts

The Fall 2023 SDS Seminar Series beings on September 8th from 2:00 p.m. to 3:00 p.m. with Dr. Emily Roberts (Department of Biostatistics, University of Iowa). This event is in-person.

Title: A Causal Inference Approach for Surrogate Marker Evaluation with Mixed Models

Abstract: In randomized clinical trials, intermediate endpoints may serve as surrogate markers for a clinical outcome of interest. Before taking advantage of such a surrogate, it is critical to carefully determine whether a candidate marker is valid for use in a future trial. This work builds on established causal inference approaches for evaluating a candidate surrogate using potential outcomes when measures of both outcomes are repeatedly collected. We do so by using the principal stratification framework and linear mixed models. This proposed framework allows us to calculate a causal effect predictiveness curve based on the distribution of random effects for both the surrogate and clinical endpoints and observed and counterfactual outcomes. Our work is primarily motivated by a diabetes clinical trial which investigated a potential treatment to protect beta cells in new onset Type 1 Diabetes patients.