The global response to the HIV epidemic has achieved remarkable increase in access to antiretroviral therapy (ART) through largely vertical programs. Whether the HIV treatment programs have strengthened the broader health system to achieve better outcomes for tuberculosis (TB) and non-communicable diseases (NCDs) is unclear. We conducted a quasi-experimental study in rural Kwazulu-Natal (KZN), South Africa to determine whether exposure to health benefits from ART utilization by a person living with HIV (PLHIV) in the household affects uptake of TB, hypertension (HTN) and diabetes (DM) treatment by other household members with these conditions.
The study was conducted in the comprehensive population cohort run by the Africa Health Research Institute (AHRI) in KZN. We linked PLHIV engaged in HIV care to their cohabiting household members aged ≥15 years using a unique identifier for homesteads. We implemented regression discontinuity quasi-experiments fitting Weibull and Cox survival models to establish the causal effect of ART utilization on uptake of TB, HTN, and DM treatment among household members. We ran unadjusted models and models adjusting for age and sex, restricting the analysis to a narrow CD4+ cell count range around the regression discontinuity threshold.
There were 4867 PLHIV enrolled in care living with 17,253 household members ≥15 years in 4212 unique homesteads between 2008-2014. Most PLHIV in care were women (77%) with mean age of 33 years. Cohabiting household members were 55% female with mean age of 31 years and a median household ART utilization exposure of 1.7 years (IQR: 0.6-3.2). During the study period, 3.0% (95.6% of those with TB), 11.4% (86.0% of those with HTN) and 3.1% (83% of those with DM) of cohabiting household members reported that they were currently being treated for TB, HTN, or DM, respectively. Household ART utilization increased treatment for diabetes (RR 1.90: 95% CI 1.07-3.40) but not for TB (RR 1.12: 95% CI 0.71-2.03) or hypertension (RR 1.31: 95% CI 0.97-1.77) (Table 1).
Household exposure to public-sector HIV treatment programs substantially increased uptake of DM treatment but not for HTN and TB treatment among household members. Future research needs to establish the mechanisms leading to these effects and how HIV treatment programs can be even better leveraged to improve access to other needed chronic care in Africa.