The cost-effectiveness of government actions to reduce sodium intake through salt substitutes in Vietnam

Abstract

Background Dietary sodium reduction is recommended to reduce the burden of cardiovascular disease. In Vietnam food products including salt, fish sauce and bot canh contribute to ~70% of dietary sodium intake. Reduced sodium versions of these products can be produced by replacing some of the sodium chloride with potassium chloride. We aimed to assess the cost-effectiveness of three alternative approaches to introducing reduced sodium products onto the market with a view to lowering population sodium intake in Vietnam.Methods The three salt substitution strategies included voluntary, subsidised and regulatory approaches targeting salt, fish sauce and bot canh products. Costs were modelled using the WHO-CHOICE methodology. A Markov cohort model was developed to evaluate the cost-effectiveness of each strategy versus no intervention from the government perspective. The model linked each intervention strategy to assumed changes in levels of sodium intake and then to systolic blood pressure. Changes in SBP were linked to a probability of ischaemic heart disease or stroke. The model followed people over their lifetime to assess average costs and quality adjusted life years (QALYs) gained for each strategy. Results The voluntary salt substitution strategy was assumed to require no investment by government. Following ramp up (years 6+), the average annual costs for the subsidised and regulatory strategies were 21,808,968,902 ₫ (US$ 977,354) and 12,949,953,247 ₫ (US$ 580,410) respectively. Relative to no intervention, all three salt substitution strategies were found to be cost-effective. Cost savings were driven by reductions in strokes (32,595; 768,384; 2,366,480) and ischaemic heart disease (IHD) events (22,830; 537,157; 1,648,590) for the voluntary, subsidised & regulatory strategies, respectively. The voluntary strategy was least cost-effective (-3,445 ₫ US$ -0.15; 0.009 QALYs gained) followed by the subsidised strategy (-43,189 ₫ US$ -1.86; 0.022 QALYs gained) and the regulatory strategy delivered the highest cost savings and health gains (-243,530 ₫ US$ -10.49; 0.074 QALYs gained). Conclusion This research shows that all three modelled salt substitution strategies would be good value for money relative to no intervention in Vietnam. The subsidised alternative would require the highest level of government investment; however the implementation costs will be exceeded by healthcare savings assuming a reasonable time horizon is considered.

Cost-Effectiveness of a Household Salt Substitution Intervention: Findings From 20 995 Participants of the Salt Substitute and Stroke Study

“…The participants in SSaSS were a high-risk population with a high level of sodium consumption who experienced large absolute benefits, 14 which is a scenario in which the cost-effectiveness of intervention might be optimized. However, given the cost-saving nature of salt substitution in SSaSS, and the favorable findings in previous modeled cost-effectiveness studies, 11–13 the SSaSS results make it highly probable that salt substitution would be cost-effective in many other populations where the majority of sodium intake derives from household consumption. 37 For populations where most dietary sodium comes from foods prepared outside the home, benefits of salt substitution could be achieved by replacing salt used as an ingredient for foods prepared at restaurants or in food manufacturing facilities.…”

“…This meant that we could avoid the need to make a series of assumptions that were common in previous estimates that modeled the cost-effectiveness of salt substitution. 11–13 There were also important limitations. The serial HSU data required for calculating QALYs were not collected as part of the trial follow-up and had to be imputed from external sources.…”

“…On the basis of modeling studies, populationwide sodium reduction is advocated by the World Health Organization as a “best buy” for the prevention of noncommunicable diseases. 10 Salt substitution in food production may also be a cost-saving or cost-effective intervention for the prevention of cardiovascular disease, 11–13 but previous model-based health economic analyses have all relied on extrapolating effects on blood pressure to reductions in clinical events. The cost-effectiveness of household salt substitution on the basis of randomized trials that assessed effects on major outcomes is unknown.…”

Avoidable burden of stomach cancer and potential gains in healthy life years from gradual reductions in salt consumption in Vietnam, 2019 – 2030: a modelling study

“…The most recent World Health Organization (WHO) STEPS survey in Vietnam estimated that adults consume on average 9.4 grams of salt per day (10), which is about double the current WHO recommendation of <5g/day (11). Existing research on the harmful effects of high salt intake globally (12) and in Vietnam (13, 14) has mostly focused on its impact on blood pressure and cardiovascular disease. The impact of such high salt diets on the burden of stomach cancer has not been evaluated in Vietnam.…”

Avoidable burden of stomach cancer and potential gains in healthy life years from gradual reductions in salt consumption in Vietnam, 2019–2030: a modelling study

“…The most recent WHO STEPS survey in Vietnam estimated that adults consume on average 9•4 g of salt/d (10) , which is about double the current WHO recommendation of <5 g/d (11) . Existing research on the harmful effects of high-salt intake globally (12) and in Vietnam (13,14) has mostly focused on its impact on blood pressure and CVD. The impact of such high-salt diets on the burden of stomach cancer has not been evaluated in Vietnam.…”