Health systems performance for hypertension control using a cascade of care approach in South Africa, 2008-2017

Background. Hypertension is a major contributor to global morbidity and mortality. In South Africa, the government has employed a whole systems approach to address the growing burden of non-communicable diseases. We used a novel incident care cascade approach to measure changes in the South African health system's ability to manage hypertension between 2008 and 2017. Methods. We used data from Waves 1-5 of the National Income Dynamics Study (NIDS) to estimate trends in the hypertension care cascade and unmet treatment need across four successive cohorts with incident hypertension. We used a negative binomial regression to identify factors that may predict higher rates of hypertension control, controlling for socio-demographic and healthcare factors. The largest cascade attrition occurred prior to diagnosis. Results. In 2011, 19.6% (95%CI 14.2, 26.2) of individuals with incident hypertension were diagnosed, 15.4% (95% CI 10.8, 21.4) were on treatment and 7.1% had controlled blood pressure. By 2017, the proportion of individuals with diagnosed incident hypertension had increased to 24.4% (95% CI 15.9, 35.4) with increases in treatment (23.3%, 95% CI 15.0, 34.3) and control (22.1%, 95% CI 14.1, 33.0) were also observed, translating to a decrease in unmet need from 92.9% in 2011 to 77.9% in 2017. Multivariable regression showed that participants with incident hypertension in 2017 were 3.01 (95% CI 1.77, 5.13) times more likely to have a controlled blood pressure compared to those in 2011. Conclusions. The proportion of people with incident hypertension who successfully progressed to controlled blood pressure tripled between 2011 and 2017 in South Africa. Despite these improvements, a low absolute proportion of the population were able to control their blood pressure and a high burden of unmet need remains.