John SeegerJohn Seeger, PharmD, MPH, DrPH, FISPE, is a pharmacoepidemiologist and Chief Scientific Officer for Epidemiology at Optum, where he has been employed for more than 20 years. He has conducted dozens of studies addressing regulatory drug safety questions across a wide range of drugs, vaccines, and disease conditions. Most of this work has involved the use of health insurance claims databases, and Dr. Seeger's methodologic expertise focuses on research issues encountered in such settings. He has worked extensively with propensity scores that seek to mitigate confounding by collapsing covariates, and he teaches several courses on propensity scores in pharmacoepidemiology. Throughout this work, Dr. Seeger has remained keenly aware of the limitations of research using administrative data and has supplemented the platform of insurance claims with additional data where appropriate, including laboratory test results, surveys, medical record reviews, and has expanded into research involving electronic health record data. Dr. Seeger is an Adjunct Assistant Professor of Epidemiology at the Harvard T.H. Chan School of Public Health. He has been active within the International Society of Pharmacoepidemiology (ISPE) and is a Past President and Fellow of the Society.