An official website of the United States government
A .mil website belongs to an official U.S. Department of Defense organization in the United States.
A lock (lock ) or https:// means you’ve safely connected to the .mil website. Share sensitive information only on official, secure websites.

Landmark 21-Year Study to Track Long-Term Health of More Than 140,000 US Service Members

  • Published
FALLS CHURCH, Va. --  Starting in May, the Department of Defense will launch the third and final recruitment phase of the largest prospective health project in military history - the Millennium Cohort Study. Designed to evaluate the long-term health effects of military service, including deployments, the cohort is tracking the health status of more than 140,000 service members from active, Reserve, and Guard duty status until well into their civilian careers or retirement. 

"We are very excited about this project," said Navy Cmdr. Margaret Ryan, a medical doctor who is the principal investigator for the study. "This ground breaking, twenty-one year venture is expected to be one of the most important and comprehensive looks at the effects military service has on long-term health."

The survey participants are chosen at random from personnel rosters of all the service branches. While cooperation is not mandatory, the program has been endorsed by Chairman of the Joint Chiefs of Staff, Gen. Peter Pace, as well as several veterans' service organizations. 

"Participating in the cohort will support the long-term health of our military forces and we hope that everyone who receives a letter in the mail in May will choose to do so," Commander Ryan said. "All participants can be assured that their identities and health information are held in the strictest of confidence within the investigation team."

While the study is entering its sixth year out of a twenty-one year study period, initial data has already sparked much interest in the medical community. "This project will usher in a new era of insight and understanding in the areas of deployment-related exposures, long-term mental health challenges, and service-related health issues to name just a few of the topics these findings will address," Commander Ryan said. 

Funded by the Department of Defense and supported by military, Department of Veterans Affairs, and civilian researchers, nearly 110,000 people are already participating in this groundbreaking study.