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.
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 led by S Teeraananchi at the Kirby Institute, University of New South Wales, Sydney and HIV-NAT, Thai Red Cross AIDS Research Centre, Bangkok, Thailand. “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.
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, US, 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.
Objectives: Life expectancy is an important indicator informing decision making in policies relating to HIV-infected people. Studies estimating life expectancy after starting combination antiretroviral therapy (cART) have noted differences between income regions. The objective of our study was to perform a meta-analysis to assess life expectancy of HIV-positive people after starting cART, and to quantify differences between low/middle- and high-income countries.
Methods: Eight cohort studies estimating life expectancy in HIV-positive people initiating cART aged ≥ 14 years using the abridged life table method were identified. Random effects meta-analysis was used to pool estimated outcomes, overall and by income region. Heterogeneity between studies was assessed with the I2 statistic. We estimated additional years of life expected after starting cART at ages 20 and 35 years.
Results: Overall life expectancy in high-income countries was an additional 43.3 years [95% confidence interval (CI) 42.5–44.2 years] and 32.2 years (95% CI 30.9–33.5 years) at ages 20 and 35 years, respectively, and 28.3 (95% CI 23.3–33.3) and 25.6 (95% CI 22.1–29.2) additional years, respectively, in low/middle-income countries. In low/middle-income countries, life expectancy after starting cART at age 20 years was an additional 22.9 years (95% CI 18.4–27.5 years) for men and 33.0 years (95% CI 30.4–35.6 years) for women, but was similar in the two sexes in high-income countries. In all income regions, life expectancy after starting cART increased over calendar time.
Conclusions: Our results suggest that the life expectancy of HIV-positive people after starting cART has improved over time. Monitoring life expectancy into the future is important to assess how changes to cART guidelines will affect patient long-term outcomes.
S Teeraananchi, SJ Kerr, J Amin, K Ruxrungtham, MG Law