Systolic Blood Pressure and Mortality in South Africa: Evidence from a Nationally Representative Cohort Study
Alpha Oumar Diallo1, Mohammed Ali2, Pascal Geldsetzer3, Emily Gower1, Trasias Mukama4, Ryan Wagner5, Justine Davies6, Maarten Bijlsma7, Nikkil Sudharsanan8
1University of North Carolina, Chapel Hill, 2Emory University, 3Stanford University, 4German Cancer Research Center, 5University of the Witwatersrand, 6University of Birmingham, 7Max Planck Institute for Demographic Research, 8Heidelberg Institute of Global Health

Improving hypertension control in sub-Saharan Africa is an important global health priority yet there is no direct evidence on the expected mortality benefits of reducing blood pressure (BP) to different targets. We use nationally representative longitudinal data from five waves of the South African National Income Dynamics Study to estimate the relationship between systolic BP (SBP) and six-year all-cause mortality and compare the number of deaths averted from scaling up SBP care under different thresholds. We found that the association between SBP and mortality is weaker in South Africa than in high-income and many low- and middle-income countries. As such, at the population level, we find that scaling up care under a more conservative 150 mmHg threshold results in the most efficient mortality benefits in terms of deaths averted (3.3 deaths averted per 1,000 population) relative to the share of the total population that would require care (16%).