Life expectancy for people with HIV in Africa may be comparable to general population if they are on treatment

Carole Leach-Lemens
Published: 18 July 2011

Life expectancy for HIV-positive adults starting antiretroviral treatment (ART) in Uganda is comparable to life expectancy for all Ugandan adults. This was reported by Edward J Mills and colleagues in a prospective cohort study of over 22,000 adults who started ART between 2000 and 2009, published today in the Annals of Internal Medicine.

Adult women had a greater life expectancy than adolescents and men.

The higher the person’s CD4 cell count when starting ART, the greater the life expectancy.

These findings mirror earlier findings from research in developed countries where ART has dramatically increased life expectancy.

Deborah Cotton, in an accompanying editorial, notes that these results clearly dispel the thinking at the turn of the century of “two AIDS realities going forward: a chronic but increasingly manageable disease in the developed world, and an unstoppable, unspeakable tragedy in Africa and other resource-constrained countries”.

What has happened in resource-poor settings in the past decade has been a “triumph of medicine and public health”, she added.

Impact of ART on life expectancy

Increased access to ART in resource-poor settings has resulted in significant decreases in death and illness, contributing to the health and welfare of families and communities.

Life expectancy and death rates reflect a population’s health. Studies show HIV prevalence has a negative impact on life expectancy rates at the population level.

A recent analysis in Europe and North America has shown that those starting ART at the age of 20 can expect to live until close to 80 years of age: an increase of more than 80% in life expectancy since 1996 – which coincides with the availability of effective HIV treatment.

Little is known, however, about life expectancy in people on ART in resource-poor settings. Knowing both the outcomes and the cost-effectiveness of ART is essential for planning and investment in the roll-out of ART programmes.  

Investment in ART needs to be understood within a broader context, with Deborah Cotton noting: “the unique nature of AIDS as a killer of young adults, of those on whom the very survival of societies depend”.

Research on life expectancy in Uganda

To estimate life expectancy among patients once they start ART, the authors used data from The AIDS Support Organization (TASO). TASO provides clinical care, psychosocial support and ART to people with HIV at 11 major clinical sites and 35 smaller clinics throughout Uganda.

Information on patients at these sites, from both before and after 2006, was assessed to see whether death rates differed between these two time periods.

Life expectancy at birth in Uganda is 55 years. 

Death rates were calculated for all causes of mortality. Life tables were built to calculate life expectancy for those on ART from ages 20 to 55, and classified according to sex and CD4 cell count.

The cohort comprised 22,315 people – aged 14 or older – who started ART between 2000 and 2009 (a total of 59,435 person-years).  Of this group, 9899 people started ART between 2000 and 2006, and were followed for a median of four years; 12,416 patients started ART between 2007 and 2009 and were followed for a median of two years.

The median age of 37 years was the same for both time periods. Median CD4 cell counts increased slightly over time from 126 cells/mm3 to 156 cells/mm3.

The estimated total number of deaths was 1943 (8.7%).

After adjusting for loss to follow-up, the crude mortality rate was considerably lower in women than in men: 26.9 deaths per 1000 person-years (95% CI: 25.4 to 28.5) and 43.9 per 1000 person-years (95% CI: 40.7 to 47.0) respectively.

The lower the CD4 cell count at baseline, the higher the risk of mortality, ranging from 67.3 deaths per 1000 person-years (95% CI: 62.1 to 72.9) with a baseline of 50 cells/mm3, to 19.1 deaths per 1000 person-years (95% CI: 16.0 to 22.7) with a baseline of 250 cells/mm3. Conversely, the higher the CD4 cell count at baseline, the greater the life expectancy.

Until very recently in resource-poor settings, ART was started when CD4 cell counts were generally under 250 cells/mm3. The limited number of people included in the study with CD4 cell counts over 250 cells/mm3 probably reduced the life expectancy estimate of those with the highest CD4 cell counts, note the authors.

Life expectancy at age 20 was 19.1 years (95% CI: 16.6 to 21.6 years) for men and 30.6 years (95% CI: 28.7 to 32.5) for women.  At age 35, life expectancy was 22 years (95% CI: 20.6 to 23.4) and 32.5 years (95% CI: 31.1 to 33.9) for men and women, respectively.

Life expectancy was consistently lower in men and adolescents than in women. As other studies have shown, men usually access care later and at a more advanced disease stage than women, note the authors.

Adolescents, they add, are usually long-term survivors infected at birth and accessing treatment only in adolescence.

These findings lead Deborah Cotton to highlight “the need to ensure systems of care are appropriately tailored to facilitate access and retention for all”.

Implications for other parts of Africa?

The authors noted this is the first evaluation of life expectancy of people with HIV in an African setting. 

One of the study’s strengths is that it is a nationally representative sample, comprising a diverse population also likely to be found in other parts of Africa, note the authors. As such, they believe these findings “are generalizable to Uganda and settings in Africa where patients access simplified HIV/AIDS care in rural, semi-rural, and urban settings”.

The authors conclude: “Our study adds to the growing body of evidence that the benefits of ART extend well beyond reduced early mortality. Widespread access to ART includes a reduction in the incidence of tuberculosis, reduced HIV transmission and increased productivity and economic benefits.” 

Political debate within the current global economic climate, Deborah Cotton notes, focuses on the greatest return on investment – often falsely pitting malaria prevention or childhood immunisation, for example, against HIV treatment.

She adds: “We now possess the tools not only to treat but to comprehensively control AIDS in Africa”, offering the potential for Africa to regain the life expectancy trajectory it was seeing before the impact of AIDS.

References

Mills EJ Life expectancy of persons receiving combination antiretroviral therapy in low-income countries: a cohort analysis from Uganda. Ann Intern Med. 155, 4, 2011.

Cotton D Life expectancy in Africa: Back to the Future. Editorial, Ann Intern Med. 155, 4, 2011.