The Veterans Aging Cohort Study (VACS) is a prospective, observational cohort study of HIV- positive and an age/race/site matched control group of HIV- negative veterans in care in the United States. The study's aim is to understand the role of comorbid medical and psychiatric disease in determining clinical outcomes in HIV infection. It is funded primarily by the National Institute on Alcoholism and Alcohol Abuse, National Institutes of Health. The study has a special focus on the role of alcohol use and abuse in determining clinical outcomes.
The VACS study is built around the Veterans Health Administration (VA), the largest integrated health-care system in the United States, providing care to 3.6 million patients annually. The VA is also the largest single provider of HIV care in the nation, serving 19,000 HIV-positive veterans in 2003. The VA provides inpatient and outpatient medical care, pharmacy, mental-health services, substance-abuse treatment, long-term care, homeless care, and hospice services. The VA also has a national, fully electronic medical-record system that includes all routine clinical data, administrative data, and comprehensive follow-up data for mortality, as the VA pays some burial expenses for veterans.