|AIDS Drugs Have Saved 3 Million Years of Life in the United
HIV Disease Model Details Survival Benefits of HIV Therapies
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, report researchers funded by the National
Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes
of Health (NIH).
Rochelle Walensky, M.D., M.P.H., Kenneth Freedberg, M.D., M.Sc., and their colleagues
calculated that advances in HIV care have yielded a total survival benefit of
2.8 million years in the United States. The researchers 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. The model projected that 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.
The paper by Drs. Walensky and Freedberg, of Massachusetts General Hospital
and the Harvard Medical School Center for AIDS Research, and their coauthors
has been posted online by The Journal of Infectious Diseases.
“Since the early 1980s, soon after the first reports of what we now know as
AIDS, NIH has devoted $30 billion to HIV/AIDS research,” says NIH Director Elias
A. Zerhouni, M.D. “This study clearly shows the dramatic impact that sustained
investment in biomedical research at NIH can have in improving the lives of Americans.”
“As new HIV therapies have come into the clinic, we have witnessed the transformation
of HIV/AIDS from a rapidly fatal disease into a controllable condition,” notes
NIAID Director Anthony S. Fauci, M.D. “Although the rate of new infections in
this country remains unacceptably high, for many people, HIV infection is no
longer the death sentence it once was.”
“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,” says Dr. Walensky.
The researchers used a computer model, developed by Dr. Freedberg and colleagues,
that incorporates literature-based data of clinical measures including HIV viral
load, CD4+ T-cell counts (a measure of immune system health), 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 U.S. Centers for Disease Control and Prevention surveillance and
other published data.
The investigators defined six eras of AIDS treatment between 1989 and 2003.
In the first two periods, 1989 to 1992 and 1993 to 1995, drugs became available
to prevent two common infections — Pneumocyctis jirovecii pneumonia
and Mycobacterium avium complex. Although the drugs provided an average
per-person survival benefit during that time of only 2.6 months, those early
eras helped to shape the perception that AIDS was a treatable condition, notes
Dr. Freedberg. Drs. Walensky and Freedberg subdivided the HAART era, which began
in 1996, into four periods corresponding to increasingly effective HAART and
other advances in HIV care.
For each year of the six eras, the investigators 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 era. The model calculated a per-person survival benefit and a total survival
benefit in each era. By 2003, the model projected that an individual beginning
treatment that year 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. The total
cumulative survival benefit across all eras from all forms of HIV therapy was
2.8 million years.
|Per-person survival benefit, number of AIDS patients
entering care and era-specific and cumulative survival benefits
|| Per Person Survival Benefit (months)
||Number of AIDS Patients Entering Care
|| Percent Surviving to Next Treatment Era
||Total Survival Benefit (Years)
|| PCP* prophylaxis
||PCP/MAC prophylaxis + ART 1
|| PCP/MAC prophylaxis + ART 2
||PCP/MAC prophylaxis + ART 3
|| PCP/MAC prophylaxis + ART 4
PCP: Pneumocystis jiroveci pneumonia
MAC: Mycobacterium avium complex
ART: antiretroviral therapy
Source: The survival benefits of AIDS treatment in the
United States. RP Walensky et al.
Dr. Walensky emphatically notes, however, that survival benefits related to
therapy are available only to those with known HIV infection. But about one-fourth
of people in the United States infected with HIV are unaware of their infection,
she adds. “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,” says Dr. Walensky. “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.”
“This type of research can also be used to understand the tremendous survival
benefits that can be gained globally by continued rapid expansion of access to
these very effective HIV/AIDS treatments in resource-limited settings,” adds
Dr. Freedberg. “This expansion is of critical importance.”
The National Institute on Drug Abuse and the National Institute of Mental Health,
parts of the NIH, also provided support for this research.
Additional Information: NIAID Exploring: Treatment of HIV Infection http://www.niaid.nih.gov/factsheets/treat-hiv.htm
News releases, fact sheets and other NIAID-related materials are available on
the NIAID Web site at http://www.niaid.nih.gov.
NIAID is a component of the National Institutes of Health. NIAID supports
basic and applied research to prevent, diagnose and treat infectious diseases
such as HIV/AIDS and other sexually transmitted infections, influenza, tuberculosis,
malaria and illness from potential agents of bioterrorism. NIAID also supports
research on basic immunology, transplantation and immune-related disorders,
including autoimmune diseases, asthma and allergies.
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the U.S. Department of Health and Human Services. It is the primary federal
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