Cost-effectiveness analysis of low-sodium potassium-rich salt substitutes in Indonesia: an equity modelling study

Background: Evidence suggests low-sodium potassium-rich salt substitutes (LSSS) are effective in reducing blood pressure (BP). However, the health and economic impacts of LSSS in Indonesia are currently unknown. Methods: We developed a proportional multistate lifetable Markov model to assess a government-led strategy implementing the use of LSSS compared to current regular salt consumption. BP data were derived from the Indonesian Basic Health Research Survey (RISKESDAS 2018), while epidemiological data were from the Global Burden of Disease 2019 study. We estimated implementation costs and the impact of changes in BP on disease events and healthcare costs, and incremental cost-effectiveness ratios. Outcomes were simulated over different time horizons for the 2019 Indonesian population overall, and by income quintiles. Probabilistic sensitivity analysis was done to capture uncertainty. Findings: Over the first 10 years, LSSS could prevent 1.5 million non-fatal cardiovascular disease (CVD) events (8.3%–19.4% reduction) and 643,000 incident chronic kidney disease (CKD) cases (8.2% reduction), while averting over 200,000 CVD and CKD deaths (0.2%–5.2% reduction). This translated to over 24.6 million health-adjusted life years (HALYs) gained over the lifetime of the population, and reduced CVD-related health inequalities (concentration index, −0.075, 95% CI: −0.088 to −0.062). Implementation cost (US$ 1.2 billion [IDR 17.2 trillion] total; US$ 4.5 [IDR 63,665] per capita, as of July 2019) was outweighed by the net health expenditure savings (∼US$ 2 billion [IDR 27.7 trillion] total; US$ 7.3 [IDR 103,300] per capita) in the first 10 years. LSSS were cost-saving over the lifetime, and very cost-effective even with a high LSSS price. Interpretation: Scaling the use of LSSS nationally could be a cost-saving strategy to prevent substantial cardiovascular and kidney disease burden in Indonesia. Funding: Griffith University Postdoctoral Fellowship.