Linking exposures and health outcomes to a large population-based longitudinal study: the Millennium Cohort Study.

OBJECTIVE To describe current efforts and future potential for understanding long-term health of military service members by linking the Millennium Cohort Study data to exposures and health outcomes. METHODS The Millennium Cohort Study launched in 2001, before September 11 and the start of combat operations in Afghanistan and Iraq. Other substantial Department of Defense (DoD) health, personnel, and exposure databases are maintained in electronic form and may be linked by personal identifiers. RESULTS More than 150,000 consenting members comprise the Millennium Cohort from all services, and include active duty, Reserve, and National Guard current and past members, and represent demographic, occupational, military, and health characteristics of the U.S. military. These prospective data offer symptom assessment, behavioral health, and self-reported exposures that may complement and fill gaps in capability presented by other DoD electronic health and exposure data. CONCLUSIONS In conjunction with Millennium Cohort survey data, prospective individual-level exposure and health outcome assessment is crucial to understand and quantify any long-term health outcomes potentially associated with unique military occupational exposures.