Cost-Effectiveness of Salt Substitution and Antihypertensive Drug Treatment in Chinese Prehypertensive Adults

BACKGROUND: Recent guidelines recommend antihypertensive drug treatment for prehypertensive individuals with blood pressure between 130/80 and 139/89 mm Hg. This study evaluates the cost-effectiveness of 3 interventions in Chinese prehypertensive adults: salt substitution, antihypertensive drug treatment, and their combination. METHODS: We developed a Markov cohort model to estimate cardiovascular disease (CVD) events, costs, and quality-adjusted life years (QALYs) over a lifetime. Data from the China Kadoorie Biobank informed the simulation. Costs and utilities were drawn from published sources. We evaluated the cost-effectiveness of salt substitution alone, antihypertensive drug treatment alone, and a combination of the 2, focusing on the overall prehypertensive population, those at high CVD risk, and different starting ages (40, 50, 60, and 70 years). Incremental cost-effectiveness ratios (ICERs) were calculated per QALY gained. RESULTS: Salt substitution at age 40 years is the only cost-effective strategy for prehypertensive individuals, with an ICER of $6413.62/QALY. For those at high CVD risk, the combination intervention starting at age 40 years is most cost-effective, with an ICER of $2913.30/QALY. Interventions initiated at younger ages yielded greater CVD reductions and lower ICERs. For example, a combined intervention at age 40 years reduces CVD events by 5.3% with an ICER of $2913.30/QALY, compared with 4.9% and $32 635.33/QALY at age 70 years. These results were consistent across sensitivity analyses. CONCLUSIONS: In China, replacing usual salt with a salt substitute is more cost-effective than treating prehypertensive individuals over the age of 40 years with antihypertensive drugs. Furthermore, starting intervention at a younger age in prehypertensive adults can result in even greater cost savings.