Examining Mechanisms of Intervention Using Statistical Mediation Methods
- Roybal Coordinating Center
- May 5
- 1 min read
Jul 10, 2025 12:00 PM ET

Dr. David L. Roth is a Professor Emeritus of Geriatric Medicine and Biostatistics at Johns Hopkins University. He was trained as a clinical psychologist and has considerable expertise as an applied statistician, with over 40 years of experience as an NIH-funded investigator. In addition to his collaborative contributions, Dr. Roth served as a Principal Investigator on multiple R01 grants that examined the health effects (and benefits) of family caregiving using data from large national epidemiological investigations. Although Dr. Roth retired from his full-time academic position in 2024, he continues to be an active scholar and serves as a consultant on multiple funded projects, including the EMBRACE Roybal Center. He has a long history of collaboration with EMBRACE Center leaders.
This presentation will introduce investigators to key decisions that must be made when testing intervention mechanistic hypotheses with statistical mediation methods. Topics will include whether change scores or post-treatment scores should be analyzed, how baseline (pre-treatment) measures should be used as covariates, the importance of selecting mediating variables with very high reliabilities, and the availability of multiple methods for testing the statistical significance of and interpreting the magnitude of the mediated effect.