Advances in combination antiretroviral therapy (cART) have added more than 13 years to the average life expectancy of people with HIV in Europe and North America since the late 1990s, an analysis of 14 cohort studies has shown.

That equated to a fall of nearly 39% in death rates over the same period for the 43,355 HIV-positives included in the analysis, a team led by Dr Robert Hogg of the British Columbia Centre for Excellence in HIV/AIDS in Vancouver, Canada reported in The Lancet. On average, though, remaining life expectancy at 20 years of age was still only around two-thirds that of the general population in these countries, the data revealed.

The research was part of the Antiretroviral Therapy Cohort Collaboration, an initiative involving researchers from the US, Canada and a number of European countries. Funding came from GlaxoSmithKline and the UK’s Medical Research Council.

Patients were included in the analysis if they were HIV-positive, aged 16 years or over and were antiretroviral-naïve when starting combination therapy. Life expectancy and other measures such as crude mortality rates were taken for the 18,587, 13,914 and 10,854 eligible patients who initiated cART in 1996-99, 2000-02 and 2003-05 respectively, with stratification for sex, baseline CD4 cell count and history of drug use by injection.

A total of 2,056 patients (4.7% of the combined cohorts) died over the whole study period, with crude mortality rates dropping from 16.3 deaths per 1,000 person-years in 1996-99 to 10.0 deaths per 1,000 person-years in 2003-05. Potential years of life lost per 1,000 person-years fell from 366 to 189 years over the same period.

Life expectancy at 20 years of age increased from 36.1 years remaining (i.e., 56.1 years in all) in 1996-99 to 49.4 years left in 2003-05. However, there was considerable variability between subgroups in this respect. Women, for example, had a longer life expectancy than men, while patients with presumed HIV transmission from injecting drugs had a lower life expectancy than patients from other transmission groups (32.6 years versus 44.7 years respectively in 2003-05).

“Since their introduction in 1996 cART regimens have become more effective, better tolerated and easier to follow,” commented Dr Michael Mugavero, one of the study authors and an assistant professor in the Division of Infectious Diseases at the University of Alabama at Birmingham in the US.

“We are now seeing the benefits of years of research, hard work and efforts to make these medications widely available,” Mugavero added. All the same, he cautioned, the dramatic improvements in life expectancy did not apply to the nearly half of all HIV-positives who are diagnosed with advanced infection.

In the Lancet report, patients treated at a later stage of infection had an average total life expectancy of 52.4 years compared with 70.4 years for patients given cART earlier on.

These figures underline the need for better AIDS testing and wider access to care. For those caught earlier in cycle, Hogg pointed out, better cART has already transformed HIV from a fatal disease into a long-term chronic condition.