DOD study ongoing to investigate Airmen’s health Published May 27, 2005 SAN ANTONIO (AFPN) -- An ongoing Department of Defense health study will ultimately examine health surveys submitted by servicemembers throughout 20 years.The joint-service Millennium Cohort Study will evaluate the health risks of military deployments, occupations and general military service, said Navy Cmdr. (Dr.) Margaret Ryan, director of the DOD Center for Deployment Health Research in San Diego.Enrollment for the study began in 2001, and close to 100,000 servicemembers have enrolled since then, including active-duty and reserve components. Of those, more than 20,000 participants are Airmen.Participants are selected and asked to complete a survey every three years through 2022. To make participation as effortless as possible, respondents have the option of completing either online surveys or paper surveys that arrive in the mail.Although enrollment has been hampered by deployments supporting operations Enduring Freedom and Iraqi Freedom, it is increasingly important for servicemembers to respond to study invitations during these periods, DOD health officials said.Results have already led to a better understanding of the general health of servicemembers, while future studies will focus on specific disease outcomes and multisymptom illnesses, officials said.