AIDS drugs have saved 3 million years of life in the U.S.

July 2006

Increasingly effective HIV therapy, including a decade of highly active antiretroviral therapy (HAART), has provided 3 million years of extended life to Americans with AIDS since 1989, according to a report published in The Journal of Infectious Diseases.

Rochelle Walensky, MD, MPH, and colleagues at the Massachusetts General Hospital and the Harvard Medical School Center for AIDS Research have determined that advances in HIV care have yielded a total survival benefit of 2.8 million years in the United States. They also estimate that drugs to prevent mother-to-child transmission of HIV have averted 2,900 infant infections, saving an additional 137,000 years of life. According to the researchers, a person initiating HIV therapy in 2003 could expect to live more than 13 years longer than if he or she had been diagnosed in 1988.

“Advances in HIV/AIDS treatments have been striking, particularly over the past decade. Our goal in this study was to quantify the clinical progress in AIDS care in terms of years of life saved,” she said.

The researchers developed and used a computer model that incorporates literature-based data of clinical measures including HIV viral load, CD4+ T-cell counts, efficacy of HAART, and incidence of opportunistic infections, to simulate HIV disease progression both with and without treatment. Information about the number of people diagnosed with AIDS and accessing health care each year between 1989 and 2003 came from CDC surveillance and other published data.

AIDS treatment was broken down into six periods between 1989 and 2003. During the first two periods, 1989 to 1992 and 1993 to 1995, drugs became available to prevent two common infections: Pneumocystis jiroveci pneumonia and Mycobacterium avium complex. The subsequent HAART era, which began in 1996, was divided into four periods that correspond with increasingly effective HAART and other advances in HIV care.

For each year of the six periods, the researchers ran simulations of HIV disease progression in two equal-sized groups of hypothetical people with AIDS. One group received no therapy, while the other group received all available therapies of that period. By 2003, the model projected that an individual beginning treatment could expect to live more than 13 years longer than if he or she had been diagnosed in 1988. The total survival benefit for the 24,780 people diagnosed with AIDS and entering care in 2003 was 330,189 years.

Walensky emphasized that survival benefits related to therapy are available only to those with known HIV. However, approximately one-fourth of people in the United States with HIV are unaware.

“We calculated that a cohort of patients presenting with AIDS at higher CD4 cell counts — simulating slightly earlier entry into care — had an additional gain of 740,000 years of survival,” she said.

“These findings underscore the importance of expanded HIV testing and better linkage to care for people who are HIV-infected, so that more of them can realize the life-extending benefits of HIV therapies.”