Population-level mortality benefits of hypothetical blood pressure lowering interventions in middle-aged and older Chinese adults: a modelling study

BACKGROUND: To study the effects of hypothetical interventions on systolic blood pressure (SBP) with mortality risk at the population level. METHODS: We used data from the China Health and Retirement Longitudinal Study (n = 12,567). Using the parametric g-formula, we estimated the number deaths averted per 1000 population, the mean SBP reduction required to achieve each target, the share of the population in need of management, and the number needed to treat (NNT) to avert one death under different hypothetical population-wide scale-up scenarios (120, 130, 140, and 150 mm Hg). RESULTS: Over a 5-year follow-up, 1092 individuals died. At the population level, reducing SBP to 120 mm Hg among all those with a starting SBP of ≥ 120 mm Hg was associated with 14.7 (95% CI: 8.3 to 21.1) deaths averted per 1000 population, compared with 2.5 (95% CI: 0.3 to 4.7) deaths averted for the 150 mm Hg scenario. However, there were large differences between scenarios in the proportion of the population that would require treatment, ranging from 66.4% in the 120 mm Hg scenario to 15.7% in the 150 mm Hg scenario. To achieve the target, the 120 mm Hg scenario required a mean shift of 13.7 mm Hg in SBP compared with a 2.3 mm Hg mean change for the 150 mm Hg scenario. However, the 120 mm Hg scenario yielded the lowest NNT (n = 46). CONCLUSIONS: These findings highlight the potential mortality benefits of reducing blood pressure at the population level.