Cost-Effectiveness Data Supports Use of Salt Substitute Based on SSaSS Findings

Data from a within-trial cost-effectiveness evaluation of data from the Salt Substitute and Stroke Study suggest use of the 75% sodium chloride 25% potassium chloride salt substitute had a 95% probability of being cost-saving and a greater than 99.9% probability of being cost-effective.

A new analysis of data from the landmark Salt Substitute and Stroke Study (SSaSS), which headlined ESC Congress 2021, is providing insight into the cost-effectiveness of a reduced-sodium salt substitute for reducing risk of stroke and cardiovascular events.

A within-trial economic evaluation from the perspective of the healthcare system and consumers, results of the cost-effectiveness analysis demonstrate an approach using a salt substitute intervention had a 95% probability of being cost-saving and a greater than 99.9% probability of being cost-effective.

“Salt substitution was cost-saving because the additional costs associated with salt substitution were offset by savings in healthcare costs, primarily through a reduction in the numbers of non-fatal events requiring hospitalization. Salt substitution also saved costs in outpatient visits and outpatient medications, although they represented a small part of the total healthcare cost,” wrote investigators.

An open-label, cluster-randomized trial conducted in 600 villages in rural areas of 5 provinces in China, the trial compared use of regular salt against substitute that was 75% sodium chloride and 25% potassium chloride by mass in more than 20,000 patients followed for a mean of 4.7 years and concluded use of the salt substitute was associated with a 14% reduction in rate of stroke, 13% reduction in rate of major adverse cardiovascular events, and a 12% reduction in rate of mortality. Results of the study were lauded for their potential impactions on health on a global level after being presented at ESC Congress 2021 by Bruce Neal, MBChB, PhD, of the George Institute for Global Health.

The within-trial economic evaluation of SSaSS, which was conducted from the perspective of the healthcare system and consumers, was designed to assess a primary health outcome of stroke and to quantify the effects of salt substitution from the trial on quality-adjusted life-years (QALYs) gained. Investigators pointed out estimates of incremental costs, stroke events averted, and QALYs gained were obtained using bivariate multilevel modeling. Investigators also pointed out all costs, which were calculated in Yuan (CNY ¥), and QALYs were discounted at 5% per year.

In their analyses, investigators determined those randomized to the salt substitute group had an average of 0.054 (95% CI, 0.012 to 0.095) more QALYs per person, which investigators noted equates to about 20 additional days in full health per person. Further analysis suggested those randomized to the salt substitute group experienced lower mean inpatient healthcare costs (CNY ¥-164, 95% CI -355 to -96), lower mean outpatient visit costs (CNY ¥-21, 95%, -38 to -4) and lower mean outpatient medication costs (CNY ¥-40, 95% CI -62 to -18). These figures correlate to mean reductions of $25.81, $3.31, and $6.30, respectively. In analysis adjusting for costs of healthcare services, total costs were on average lower among those in the substitute group (CNY ¥-110 [95% CI, -239 to -19]). This figure correlates to a mean reduction in total costs of $17.31.

Sensitivity analysis demonstrated the aforementioned conclusions were robust, except when adjusting the price of the substitute to the median and highest market prices identified in China. Additionally, investigators underlined the salt substitute intervention had a 95% probability of being cost-saving and a greater than 99.9% probability of being cost-effective.

“Salt substitution is the only salt reduction intervention with grade one evidence demonstrating cost-saving protection against clinical events and should now be considered by all countries planning or implementing sodium reduction campaigns. Salt substitution should be particularly high up the priority list for countries where a large proportion of dietary sodium derives from ‘discretionary salt’ that can be easily substituted,” investigators added.

This study, “Cost-effectiveness of a Household Salt Substitution Intervention: Findings From 20,995 Participants of the Salt Substitute and Stroke Study (SSaSS),” was published in Circulation.

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