Progress in HIV care has saved at least 2 million years of life in the United States, according to the results of a study that quantified the total impact of HIV treatment in the US for the first time.

The researchers also found that the survival benefits of HIV treatment surpass those obtained with some other commonly used interventions for cancer and coronary artery disease.

“More than anything else, our results speak to the clinical and public health imperative to promote and finance routine, voluntary HIV screening for all adults in the United States,” lead author Dr. Rochelle Walensky said Friday during the 12th Annual Retrovirus Conference.

Walensky, of Harvard Medical School in Boston, and colleagues estimated the cumulative survival benefits of highly active antiretroviral therapy (HAART) and opportunistic infection prophylaxis in the US from 1989 to 2003. They used published estimates of the number of adults with AIDS who received the recommended standard of care in the year of diagnosis.

“What we found is that 2 million years of life have been saved as a direct and attributable result of progress in HIV care,” she said. “Whenever possible, we sought to underestimate the effects of care. Thus we understated the number of eligible patients, we understated the efficacy of treatment, and we understated the rate of linkage to care. Still, we got 2 million.”

Her group also found that “most of the survival gain is attributable to antiretroviral therapy.” They estimated that HAART “can lengthen the lifespan of persons with AIDS by nearly 15 years.”

“This kind of survival benefit,” she pointed out, “far exceeds that which can currently be achieved for patients with other chronic diseases, including chemotherapy for breast cancer, bypass surgery for coronary artery disease and marrow bone transplantation for non-Hodgkin’s lymphoma.”

They also found that zidovudine treatment averted about 2860 new cases of HIV infection in infants, which resulted in another 186,790 years of life gained. The survival benefit would have increased to 277,150 years had all pregnant HIV-infected women received zidovudine.

However, the benefits of treatment can only be achieved if those who need therapy receive it, Walensky added.

“There are 900,000 persons infected with HIV in this country; of these, as many as 280,000 don’t know it,” she said. “These are the life years we have failed to save. Instead of 2 million years of life, we could have saved over 4 million years had we identified and linked these people to care.”