Background: - Raised blood pressure, the principal cause of cardiovascular mortality globally, is common in South Africa and responsible for over 60000 deaths and 1.4 million Disability Adjusted Life Years (DALYs) in 2019. Clinically effective pharmacologic treatments to reduce blood pressure exist and evidence suggests that their uptake is on the rise in the South African population. Little is known, however, on the actual impact of this increased uptake in terms of averted morbidity and mortality. Methods: - We used harmonised data from 10 nationally representative population surveys conducted between 1998 and 2017. Using a comparative risk assessment methodology, we estimated year, age and sex-specific number of deaths and DALYs attributable to raised systolic blood pressure in the population aged 25+ years. We compared the results with a counterfactual scenario in which the impact of treatment was estimated by censored regression and removed. Results: - In 1998 – with 13.5% of women and 7.0% of men on antihypertensive treatment – 164 deaths and 3 617 DALYs per 100000 women and 163 deaths and 4 521 DALYs per 100000 men were attributable to raised blood pressure. In the counterfactual scenario, an additional 106 deaths and 2657 DALYs would have been observed per 100000 women, with an additional 59 deaths and 1695 DALYs per 100000 men. Consistently with the rising treatment penetration, the prevented burden increased over time, and in 2017 – with 32.5% of women and 23.0% of men treated – an additional 524 deaths and 9693 DALYs would have been observed per 100000 women, with 123 additional deaths and 4726 additional DALYs per 100000 men. In absence of treatment, the observed burden would have been more than double among men and more than triple among women. Conclusions: - During the study period, access to pharmacologic treatment contributed significantly to limiting the burden of disease attributable to raised blood pressure, despite the concomitant large increase of associated major risk factors, chiefly obesity.
