Mass HIV Treatment and Sex Disparities in Life Expectancy: Demographic Surveillance in Rural South Africa

Abstract

Background: Women have better patient outcomes in HIV care and treatment than men in sub-Saharan Africa. We assessed--at the population level--whether and to what extent mass HIV treatment is associated with changes in sex disparities in adult life expectancy, a summary metric of survival capturing mortality across the full cascade of HIV care. We also determined sex-specific trends in HIV mortality and the distribution of HIV-related deaths in men and women prior to and at each stage of the clinical cascade.

Methods and findings: Data were collected on all deaths occurring from 2001 to 2011 in a large population-based surveillance cohort (52,964 women and 45,688 men, ages 15 y and older) in rural KwaZulu-Natal, South Africa. Cause of death was ascertained by verbal autopsy (93% response rate). Demographic data were linked at the individual level to clinical records from the public sector HIV treatment and care program that serves the region. Annual rates of HIV-related mortality were assessed for men and women separately, and female-to-male rate ratios were estimated in exponential hazard models. Sex-specific trends in adult life expectancy and HIV-cause-deleted adult life expectancy were calculated. The proportions of HIV deaths that accrued to men and women at different stages in the HIV cascade of care were estimated annually. Following the beginning of HIV treatment scale-up in 2004, HIV mortality declined among both men and women. Female adult life expectancy increased from 51.3 y (95% CI 49.7, 52.8) in 2003 to 64.5 y (95% CI 62.7, 66.4) in 2011, a gain of 13.2 y. Male adult life expectancy increased from 46.9 y (95% CI 45.6, 48.2) in 2003 to 55.9 y (95% CI 54.3, 57.5) in 2011, a gain of 9.0 y. The gap between female and male adult life expectancy doubled, from 4.4 y in 2003 to 8.6 y in 2011, a difference of 4.3 y (95% CI 0.9, 7.6). For women, HIV mortality declined from 1.60 deaths per 100 person-years (95% CI 1.46, 1.75) in 2003 to 0.56 per 100 person-years (95% CI 0.48, 0.65) in 2011. For men, HIV-related mortality declined from 1.71 per 100 person-years (95% CI 1.55, 1.88) to 0.76 per 100 person-years (95% CI 0.67, 0.87) in the same period. The female-to-male rate ratio for HIV mortality declined from 0.93 (95% CI 0.82-1.07) in 2003 to 0.73 (95% CI 0.60-0.89) in 2011, a statistically significant decline (p = 0.046). In 2011, 57% and 41% of HIV-related deaths occurred among men and women, respectively, who had never sought care for HIV in spite of the widespread availability of free HIV treatment. The results presented here come from a poor rural setting in southern Africa with high HIV prevalence and high HIV treatment coverage; broader generalizability is unknown. Additionally, factors other than HIV treatment scale-up may have influenced population mortality trends.

Conclusions: Mass HIV treatment has been accompanied by faster declines in HIV mortality among women than men and a growing female-male disparity in adult life expectancy at the population level. In 2011, over half of male HIV deaths occurred in men who had never sought clinical HIV care. Interventions to increase HIV testing and linkage to care among men are urgently needed.

Fig 1. Adult life expectancy and HIV-cause-deleted adult life expectancy, 2001–2011, by sex.

Solid symbols are annual estimates of adult life expectancy; open symbols are annual estimates of HIV-cause-deleted adult life expectancy. 95% CIs are shown. The black dashed line indicates the beginning of ART scale-up in 2004.

Fig 2. Female–male difference in adult life expectancy, 2001–2011.

Solid blue circles display annual estimates of the gap between female and male adult life expectancy. The red dashed line indicates the gap in HIV-cause-deleted life expectancy observed in 2011. The black dashed line indicates the beginning of ART scale-up in 2004.

Fig 3. Sex-specific survival curves: 2003, 2011, and HIV-cause-deleted.

Sex-specific continuous-time Kaplan-Meier survival curves for 2003 and 2011 are shown. The HIV-cause-deleted survival curves pool person-time for 2001–2011. These are period (synthetic cohort) survival curves reflecting age-specific mortality rates in a population in a given period of time; life expectancy is calculated as the area under the curve. A risk table showing persons at risk and deaths at each age for each of the six survival curves is available as S1 Table.

Fig 4. Female-to-male HIV mortality rate ratios by age and calendar year, 2001–2011.

Age-specific HIV mortality rate ratios for women versus men were estimated in an exponential hazard regression model that included calendar year indicators for each age group and interactions for each age and year with sex. The 45–64 y and 65+ y age groups were combined to improve precision at older ages. The pooled estimate is from a separate regression model. Mortality rate ratios declined after 2004 in all age groups.

Fig 5. Distribution of HIV deaths across cascade of care, 2001–2011.

We excluded all deaths that occurred within 3 mo of migrating into the DSA, as the deceased may not have had the opportunity to seek HIV care in the local health system.