John Seeger is a pharmacoepidemiologist and Chief Scientific Officer at Optum Epidemiology. He is also Adjunct Assistant Professor in Epidemiology at the Harvard School of Public Health. Dr. Seeger has conducted dozens of studies that have addressed regulatory drug safety issues across a wide range of drugs and disease conditions. Most of this work has involved the use of health insurance claims databases as platforms for pharmacoepidemiology, so Dr. Seeger's methodological expertise focuses on research issues encountered in such settings. He has worked extensively with propensity scores and related methods that mitigate confounding by collapsing covariates. Additionally, he is a co-instructor in courses on propensity scores and is the past President of the International Society for Pharmacoepidemiology (ISPE).