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

Abstract

IntroductionHypertension 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.MethodsHypertension 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.ResultsIn 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.ConclusionsThere 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.

Universal coverage but unmet need: National and regional estimates of attrition across the diabetes care continuum in Thailand

“…Our absolute losses of -33% at screening, and -66% at diagnosis in Thailand are slightly better for screening and slightly worse for diagnosis compared to other diabetes care cascade studies in South Africa (absolute losses -45% at screening, -60% at diagnosis), and globally in 28 low-and-middle income countries (absolute losses -37% at screening, -56% at diagnosis) https://doi.org/10.1371/journal.pone.0226286.g003 [12][13][14]. The United States fares the worst among these cascades, with an absolute loss of -72% at diagnosis [16].…”

“…Care cascades were originally used to model loss to follow up in HIV/AIDS care and have subsequently been applied to a range of other chronic conditions, including hypertension and diabetes [10,11]. Prior studies using data across multiple LMIC, for example, revealed large gaps between screening and diagnosis, with 80% unmet need in diabetes care [12][13][14].…”

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“…We treated missing data, therefore, as itself a result rather than the absence of findings. However, in addition to evaluating SEARCH's effectiveness in HTN care relative to care delivery intent (i.e., its fidelity to the algorithm above), we also measured its impact in achieving key results in HTN control (i.e., its effect on care outcomes), via a series of steps validated in HTN control studies globally [42,43]. The cascade sequence of fidelity steps is displayed in the Results section.…”

Registration of amiloride in South Africa: Cutting the Gordian knot

“…In SA, hypertension is one of the leading causes of death, and 50% of treated hypertensive patients are not controlled. [17] In the USA, the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study showed that African Americans are more likely to be diagnosed with hypertension, more likely to be treated, more likely to be treated intensively, and less likely to achieve BP control. [18] Although the reasons are complex, including poor adherence and lack of access to antihypertensive medication, it is now apparent that a large proportion of uncontrolled hypertension in blacks is due to polymorphisms in genes that increase ENaC function, resulting in salt and water retention, with suppressed renin and aldosterone.…”