Quantifying unmet need for hypertension care in South Africa through a care cascade: evidence from the SANHANES, 2011-2012

Abstract

Introduction: Hypertension has become a major cause of morbidity and premature mortality in South Africa, but population-wide estimates of prevalence and access to care are scarce. Using data from the South African National Health and Nutrition Examination Survey (2011-2012), this analysis evaluates the national prevalence of hypertension and uses a care cascade to examine unmet need for care.

Methods: Hypertension was defined as blood pressure over 140/90 mm Hg or use of antihypertensive medication. We constructed a hypertension care cascade by decomposing the population with hypertension into five mutually exclusive and exhaustive subcategories: (1) unscreened and undiagnosed, (2) screened but undiagnosed, (3) diagnosed but untreated, (4) treated but uncontrolled and (5) treated and controlled. Multivariable logistic regression models were used to explore factors associated with hypertension prevalence and diagnosis.

Results: In South Africans aged 15 and above, the age standardised prevalence of hypertension was 35.1%. Among those with hypertension, 48.7% were unscreened and undiagnosed, 23.1% were screened but undiagnosed, 5.8% were diagnosed but untreated, 13.5% were treated but uncontrolled and 8.9% were controlled. The hypertension care cascade demonstrates that 49% of those with hypertension were lost at the screening stage, 50% of those who were screened never received a diagnosis, 23% of those who were diagnosed did not receive treatment and 48% of those who were treated did not reach the threshold for control. Men and older individuals had increased risks of being undiagnosed after controlling for other factors.

Conclusions: There is significant unmet need for hypertension care in South Africa; 91.1% of the hypertensive population was unscreened, undiagnosed, untreated or uncontrolled. Data from this study provide insight into where patients are lost in the hypertension care continuum and serve as a benchmark for evaluating efforts to manage the rising burden of hypertension in South Africa.

Keywords: South Africa; blood pressure; care continuum; cascade of care; health disparities; hypertension; non-communicable diseases; sanhanes; south african national health and nutrition examination survey; treatment cascade.

Figure 1

Hypertension care cascade criteria.

Figure 2

The hypertension care cascade, South Africa 2011–2012. Of those with hypertension, 51% have ever been screened for hypertension, a 49% loss. Of those who have ever had their blood pressure measured, 50% received a diagnosis of high blood pressure, a 49% loss. Of those who received a diagnosis, 77% were being treated with blood pressure medication, a 23% loss. Of those who had taken blood pressure medication in the last 30 days, 52% had controlled blood pressure (<140/90 mm Hg), a 48% loss.