Cohort profile update: the US Millennium cohort study-evaluating the impact of military experiences on service members and Veteran health

Abstract: This paper provides an update to the original cohort profile paper published a decade ago. The Millennium Cohort Study is the largest, longest-running, prospective study of current and former United States (US) military personnel and is sponsored by the US Departments of Defense (DoD) and Veterans Affairs (VA). While the original study aim, evaluating the health impact of serving in the military, has remained consistent, the spectrum of research topics has expanded to include areas such as social determinants of health. 260 228 military personnel enrolled across 5 panels between 2001 and 2021 (baseline age range: 25-35 years); participants are surveyed every 3-5 years. The original 21-year follow-up period was extended through 2068 to examine health across the lifespan. Longitudinal survey data are linked to data from DoD, VA, and external sources (e.g. medical records, deployment histories, vital statistics, and geospatial data).