Life expectancy of HIV patients increases

Improvements in and long-term effectiveness of cART have seen life expectancy increase by some 13 years from 1996-99 to 2003-05, and an accompanying drop in mortality of nearly 40 per cent in the same period.

However, life expectancy in these patients remains well short of the general population, and patients treated late in the course of their infection have worse life expectancy.

Since cART was introduced in 1996, combination therapy regimens have become more effective, better tolerated, and have been simplified in terms of dosing.  However, the effect of HIV on life expectancy in the era of combination therapy is not well understood due to the relative novelty of this treatment.

Professor Jonathan Sterne of Bristol University's Department of Social Medicine and Professor Robert Hogg of British Columbia Centre for Excellence in HIV/AIDS and Simon Fraser University, Burnaby, Canada and colleagues from The Antiretroviral Therapy Cohort Collaboration (ART-CC) compared changes in mortality and life expectancy among HIV-positive individuals on cART.

This collaboration of 14 studies in Europe and North America analysed 18,587, 13,914, and 10,584 patients who started cART in 1996-99, 2000-02, and 2003-05 respectively.

A total of 2,056 patients died during the study period, with mortality decreasing from 16.3 deaths per 1000 person-years to in 1996-99 to 10.0 in 2003-05 - a drop of around 40 per cent.

Potential life years lost per 1000 person-years also decreased over the same time, from 366 to 189 - a fall of 48 per cent.  Life expectancy increased from 36.1 years in 1996-99 to 49.4 years in 2003-05, an increase of more than 13 years.

Patients treated later in the course of their infection, with lower CD4+ cell counts (below 100 cells per ìl blood at initiation of cART), had shorter life expectancy, at 32.4 years, compared with 50.4 years in patients treated at earlier stages with higher CD4 loads (above 200 cells per ìl).

Patients with presumed transmission via injecting drug use had a shorter life expectancy (32.6 years) than those from other transmission groups (44.7 years).  Finally, women had a slightly longer life expectancy than men (44.2 v 42.8 years), which may be due to women on average starting their treatment earlier in the course of HIV-infection.

Despite these positive results, an HIV-positive person starting cART at age 20 will only, on average, live another 43 years (to age 63), while a 20- year-old HIV-negative person in a high-income country can expect to live to around 80 years, a difference of nearly 20 years. This last finding leads the authors to call on health planners to improve health services and living conditions for HIV-infected patients to reduce this gap.

Professor Sterne said: "The progressive reductions in mortality and gains in life expectancy over the three periods studied here are probably the result of both improvements in therapy during the first decade of cART and continuing declines in mortality rates among individuals on such treatment for long periods. 

"These advances have transformed HIV from being a fatal disease, which was the reality for patients before the advent of combination treatment, into a long-term chronic condition.

"The results of this study indicate that people living with HIV in high-income countries can expect increasing positive health outcomes on cART. The marked increase in life expectancy since 1996 is a testament to the gradual improvement and overall success of such treatment."

Paper: 'Life expectancy of individuals on combination antiretroviral therapy in high-income countries: a collaborative analysis of 14 cohort studies' by The Antiretroviral Therapy Cohort Collaboration. Lancet 2008; 372: 293-99.