Life expectancy of people starting HIV therapy differs sharply between high- and middle/low-income countries

There are significant disparities in the life expectancy of HIV-positive people starting combination antiretroviral therapy (cART) between world regions, according to the results of a meta-analysis published in HIV Medicine. In high-income countries, a 20 year old starting treatment was calculated to have a total life expectancy of 63 years, but in low/middle-income countries men starting treatment at that age had a total life expectancy of 43 years and women a life expectancy of 53 years. Life expectancy improved over time, reflecting improvements in HIV treatment and care.

“This is the first meta-analysis study to estimate the life expectancy of people living with HIV after starting cART by income region,” write the authors. “We found that life expectancy after starting cART differed markedly between income regions. There were no gender differences in life expectancy in high-income countries, but life expectancy was consistency higher in women than men in low/middle income countries.”

The introduction of cART in 1996 was immediately accompanied by a reduction in HIV-related mortality. Individual studies have reported improvements in the prognosis of people treated with cART, with the results of some suggesting that the life expectancy of individuals doing well on antiretrovirals is now normal.

Glossary

meta-analysis

When the statistical data from all studies which relate to a particular research question and conform to a pre-determined selection criteria are pooled and analysed together.

middle income countries

The World Bank classifies countries according to their income: low, lower-middle, upper-middle and high. There are around 50 lower-middle income countries (mostly in Africa and Asia) and around 60 upper-middle income countries (in Africa, Eastern Europe, Asia, Latin America and the Caribbean).

low income countries

The World Bank classifies countries according to their income: low, lower-middle, upper-middle and high. While the majority of the approximately 30 countries that are ranked as low income are in sub-Saharan Africa, many African countries including Kenya, Nigeria, South Africa and Zambia are in the middle-income brackets. 

prognosis

The prospect of survival and/or recovery from a disease as anticipated from the usual course of that disease or indicated by the characteristics of the patient.

inclusion criteria

The conditions which a person must meet to join a research study.

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Investigators wished to establish a better understanding of the life expectancy of HIV-positive people starting cART and to determine the extent to which prognosis differed between high- and middle/low- income countries.

They therefore performed a meta-analysis of studies reporting on life expectancy of cART-treated people.

The inclusion criteria were strict. Studies were required to be cohort studies of adult HIV-positive people who were taking a combination of three antiretrovirals. The studies were required to systematically report on life expectancy at age of starting cART. Mortality data had to be gathered through active patient follow-up.

A total of eight studies met their inclusion criteria. The articles reported on patient cohorts in Europe, Canada, the UK, USA, Rwanda, Uganda and South Africa. The studies in high-income countries were conducted between 1996 and 2011 and the papers on middle/low-income countries reported on research conducted between 2001 and 2011.

The investigators reported on life expectancy after cART initiation at the ages of 20 and 35 years.

The studies included a total of 154,670 individuals, 58% of whom were men. The cohorts in high-income countries were largely composed of men who have sex with men.

The median age at cART initiation was 37 years and the median CD4 count at the time treatment was started was between 100 and 300 cells/mm3.

The pooled life expectancy from all the studies was 37 years and 29 years from starting cART at the ages of 20 and 35 years, respectively. On average, a 20 year old starting cART would be expected to live until 57, whereas a 35 year old would live until 64. There was significant heterogeneity in both estimates.

Life expectancy was then stratified according to world region and income level.

Overall, life expectancy in high income countries was estimated to be 43 years if starting cART at the age of 20 (i.e. total life expectancy of 63 years) and 32 years when cART was started at the age of 35 (i.e. total life expectancy of 67 years).

In middle/low-income countries life expectancy differed by gender.

Additional years of life when starting cART at the age of 20 years was 23 years for men and 33 years for women (men total life expectancy of 43 years; women total life expectancy of 53 years). At the age of 35 years, life expectancy was 22 years for men (total life expectancy of 57 years) and 30 years for women (total life expectancy of 65 years).

The authors believe the disparities in life expectancy by gender in middle/low-income countries reflect differences in access to HIV testing, diagnosis and retention in care.

There was a consistent trend for life expectancy to increase with more recent calendar year of cART initiation. For example, a 35-year-old initiating cART in a high-income country between 2006 and 2008 had a total life expectancy of 71 years. “We believe that this is probably attributable to improvements in drug treatment, changing guidelines that advocate starting cART with higher CD4 counts in all settings, better adherence and support programmes, increased CD4 and viral load monitoring, and cART scale-up with increased access to care in low/middle-income countries over time,” comment the investigators.

They conclude it is important for all countries to continue to monitor the life expectancy of people starting cART in order to assess the effect of changes in treatment guidelines, care coverage and care cascades.

Note: a previous version of this article incorrectly stated that a 20-year-old initiating cART in a high-income country between 2006 and 2008 had a total life expectancy of 71 years. This should read "a 35-year-old".

References

Teeraananchai S et al. Life expectancy of HIV-positive people after starting combination antiretroviral therapy: a meta-analysis. HIV Medicine. DOI: 10.1111/hiv.12421, 2016.