HIV positive patients in high income countries have experienced an
increase in life expectancy by approximately 13 years between 1996-1999
and 2003-2005, with a concurrent drop in mortality of almost 40%. That
said, this population's life expectancy is still below that of the
general population, and life expectancy is worse when treatment is
later in the progression of the disease. These conclusions were
published in an article released on July 25, 2008 in The
Combination antiretroviral therapy (cART) was introduced as a therpay for HIV patients in 1996. Since then, combination treatment regimens have undergone many improvements, including becoming more effective, better tolerated, and having simpler dosing methods. In light of improvements, the relationship between HIV infection and life expectancy has not yet been well characterized.
To help describe this relationship, Professor Robert Hogg and Professor Jonathan Sterne and colleagues from the The Antiretroviral Therapy Cohort Collaboration (ART-CC) compared the mortality and life expectancy of HIV-positive individuals on cART. A collaboration of 14 studies in Europe and North America were performed: between 1996 and 1999, with 18,587 subjects; between 2000 and 20002, with 13,914 subjects, and between 2003 and 2005 with 10,584 subjects.
In total, 2,056 patient died over the course of the study. Initially, the population displayed mortality rates of 16.3 deaths per 1,000 person-years, but by the last time group this mortality had dropped to 10 deaths per 1,000 person-years, indicating a decrease in mortality of approximately 40%. The number of potential life years lost also decreased, beginning at 366 in the 1996 group and ending at 189, indicating a decrease of 48%. Life expectancy at the beginning of the study was 36.1 years and increased to 49.4 years in the 2003-2005 group.
There were some trends within the populations as well.
- Patients with a longer period of infection before beginning treatment and lower CD4+ cell counts, defined as fewer than 100 cells per μl blood at initiation of treatment, had a shorter life expectancy in comparison with their earlier-action, higher CD4+ counterparts. (32.4 years versus 50.4 years)
- Patients who presumably acquired the disease from injection drug use also had a shorter life expectancy in contrast with those who acquired the disease from another method. (32.6 years versus 44.7 years)
- Women generally had a longer life expectancy than men. (44.2 years versus 42.8 years) This may have been due to an average earlier treatment time relative to infection.
The authors note the improvement in treatment methods that have helped these advances. "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. "
They conclude with a comment about the health future for HIV patients in high-income countries: "In summary, 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."
Dr David Cooper, National Centre in HIV Epidemiology and Clinical Research, University of New South Wales, Sydney, Australia, contributed an accompanying comment in which he places an emphasis on the disparity between outcomes for patients with higher and lower CD4 cell counts at the start of treatment. He anticipates the imminent results of the START study, which will compare these groups as well as potential early immune activation in HIV-infected individuals, saying that it "is perhaps the most important clinical trial that should be done in the post-cART era."
Life expectancy of individuals on combination antiretroviral therapy in high-income countries: a collaborative analysis of 14 cohort studies
The Antiretroviral Therapy Cohort Collaboration
Lancet 2008; 372: 293-99
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Life and death in the cART era
David A Cooper
Lancet 2008; 372: 266-7
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Written by Anna Sophia McKenney