BOSTON – Optimally treated patients with HIV are living longer than ever, and have narrowed but not completely closed the gap in life expectancy with their uninfected peers, investigators in a large cohort study reported.

In 1996, a 20-year-old infected with HIV could expect to live only 19 more years, to age 39. In 2011, the additional life expectancy for a 20-year-old HIV-positive subject was 53 years, meaning that given survival to age 20, he or she could expect to live to age 73, said Julia L. Marcus, Ph.D., from Kaiser Permanente Northern California in Oakland.

She and her colleagues studied life expectancy in a cohort of nearly 25,000 Kaiser Permanente California members who were HIV-positive and more than 250,000 HIV-negative members in an effort to better delineate differences in survival by HIV status than in earlier comparisons.

“This is the first study to our knowledge to directly compare life expectancy by HIV status, accounting for individual-level factors and access to health care. We have complete ascertainment of deaths, and therefore no loss to follow-up, and our results are generalizable to the broader insured population,” Dr. Marcus said at the Conference on Retroviruses and Opportunistic Infections.

The study results reflect the remarkable improvement in care of insured HIV-positive patients with the introduction of antiretroviral therapy (ART), which has allowed more than half of all HIV-positive individuals to live to age 50 or older, she said.

Previous studies suggesting that there is still a gap in life expectancy between HIV-positive and HIV-negative people had compared HIV-positive individuals with the general population, limiting their ability to account for differences in life expectancy by HIV status because of differences in sociodemographic factors, access to care, and risk factors that may affect survival, Dr. Marcus said.

To overcome these limitations, the investigators compared life expectancies for 24,768 HIV-positive people who were members of Kaiser Permanente California at any time from 1996 through 2011 with those of 257,600 HIV-negative members.

They conducted estimates by year of study follow-up, sex, race/ethnicity, HIV risk group, CD4 counts at ART initiation, and by key modifiable risk factors including viral hepatitis, drug and alcohol abuse, and smoking.

They found that over the course of the study, mortality rates among HIV-negative members remained relatively stable, at 439 per 100,000 person-years (py) in 1996, to 381/100,000 in 2011. In contrast, there was a steep decline among HIV-positive members, from 7,077/100,000 py in 1996, to 1,054/100,000 py in 2011.

Among women, remaining life expectancy at age 20 among those who were HIV-negative was 65 years in 1996, and 64 in 2011. In contrast, HIV-positive women saw an increase from 37 years in 1996 to 51 in 2011. Yet at the latest time point, there was still a 13-year gap in expectancy between HIV-negative and HIV-positive women.

Among HIV-negative men at age 20, additional life expectancy remained at 62 years throughout the study period, whereas among HIV-positive men it improved from 38 years in 1996 to 49 years in 2011. But here, too, there remained a 13-year gap in expectancy between HIV-positive and HIV-negative subjects.

An analysis of life expectancies at age 20 by race/ethnicity showed similar significant gains throughout the study period for whites, blacks, and Hispanics (P less than .0010), although HIV-positive whites and Hispanics did slightly but significantly better than blacks (P = .007 and .001, respectively),

There were also significant gains in life expectancy among men having sex with men, from 40 years in 1996 to 51 years in 2011, heterosexuals, from 38 years to 51 years, and among injectable drug users, from 36 to 46 years.

To see whether they could account for the 13-year gap that remained between HIV-positive and HIV-negative members, the authors looked at various care- and disease-related factors. When they considered those patients who received optimal therapy, with ART initiated when their CD4 counts were 500 or above, the expectancy gap narrowed to 7.9 years.

When they controlled for patients without hepatitis B or C infections, the gap narrowed to 7.2 years. HIV-positive patients with no drug or alcohol abuse had only 6.8 years less life expectancy than their HIV-negative counterparts, and those who did not smoke had only a 5.4 year life-expectancy decrement.

In the question-and-answer session following Dr. Marcus’ talk, an attendee suggested that some of the remaining gap may be explained by mental health differences between HIV-positive and HIV-negative patients.

“I would urge that you start looking at mental health issues and depression in particular, which is both vastly more common in people with HIV, and also has a demonstrable impact on mortality. That may explain some of the gap,” he said.

Dr. Marcus agreed about the importance of looking at this question, and noted that it is being actively explored in ongoing studies.

Dr. Marcus disclosed that she has been supported by a research grant to her institution from Merck.

HIV-positive life expectancy improves, but gap remains