Cardiovascular disease and impoverishment averted due to a salt reduction policy in South Africa: an extended cost-effectiveness analysis

Authors: David Watkins, Zach Olson, Stéphane Verguet, Rachel Nugent, Dean Jamison

Abstract:

In response to the increasing burden of hypertension-related cardiovascular disease (CVD) in South Africa, the government recently set policy targets to reduce population salt consumption to five grams per person daily. While available evidence suggests that salt reduction could reduce CVD substantially, little is known about the policy’s impact on household and public finances. This study uses the extended cost-effectiveness analysis (ECEA) methodology to model the health and economic impact of South Africa’s salt policy targets.

Methods and Findings:

We used survey data on blood pressure, income, and salt consumption to estimate changes in age- and sex-specific CVD death rates and incidence using published effect sizes and epidemiologic studies. We modeled the average cost of CVD care by income quintile using published facility fee schedules and drug prices, then estimated total out-of-pocket (OOP) costs and government subsidies averted. We calculated financial risk protection (FRP) in terms of catastrophic health expenditures (CHE) and cases of poverty averted using published thresholds, and we performed a sensitivity analysis.

We estimated that the policy could avert 5500 deaths and 23,000 cases of CVD per year in the population. The government could save up to US$ 51.25 million in subsidies on hypertension and CVD treatment for poorer individuals. Preventing CVD could also provide substantial FRP beyond the government’s current subsidy efforts, particularly in income quintiles two, three, and four.  Our results were most sensitive to the CVD mortality inputs as well as the CVD cost estimates.

Conclusions:

South Africa’s salt policy could reduce total CVD mortality by 11% and result in large government savings. The policy would also protect many households from financial risk, particularly in the middle class. More empirical research is needed on the epidemiology of salt consumption, CVD mortality, and cost of CVD care. Future modeling studies could incorporate estimations of long-term economic impacts. The ECEA methodology is a useful analytic approach to evaluating public health policies, particularly when FRP and equity are of high priority to decision-makers.