A salt substitute that contains less sodium was a cost-effective intervention for prevention of stroke and improved quality of life, according to an analysis published in the journal Circulation.
A previous study found the substitute was effective at preventing stroke and heart attack, so these findings further cement this intervention’s usefulness, according to Darwin Labarthe, MD, PhD, MPH, professor of Preventive Medicine in the Division of Epidemiology and a co-author of the study.
“Because hypertension is so highly prevalent, and costs of its morbidity and mortality outcomes are so great, a cost-saving intervention has huge implications for national health expenditures,” Labarthe said.
Reducing salt intake reduces blood pressure, which is a primary contributor to disease and death from heart attack or stroke. As many as one billion people around the world have uncontrolled high blood pressure, Labarthe said, and that number only continues to grow.
Salt substitutes — in this study, a salt made of a mix of sodium chloride and potassium chloride — have been shown to reduce blood pressure. A previous study of more than 20,000 individuals in 600 villages in northwestern China found rates of stroke, major cardiovascular events and death were all lower in participants using salt substitutes when compared to participants using regular salt.
In the current study, investigators performed a cost-effectiveness analysis of the previous study, measuring health outcomes in quality-adjusted life years (QALYs). Healthcare costs were identified from participant health insurance records and estimated using figures from previous studies.
Over the nearly five-year follow-up period, replacing regular salt with salt substitute reduced the risk of stroke by 14 percent. The salt substitute group had on average 0.054 more QALYs per person. The average annual costs were lower in the salt-substitute group: 1,538 Chinese yuan (about $241) for the intervention group and 1,649 Chinese yuan (about $259) for the control group.
This means the intervention was dominant — a term used in cost-effectiveness denoting better outcomes at lower cost — for prevention of stroke. Sensitivity analyses performed by the authors showed these conclusions held even when the price of salt substitutes was raised, only losing cost-effectiveness when the price was increased to the highest market prices identified in China.
“This presents powerful ‘hard outcome’ evidence long demanded by sodium reduction skeptics who failed to see the value of interventions that would lower blood pressure itself, despite it being an immense health and public health problem,” Labarthe said.
This intervention holds promise, especially in countries such as China where large segments of the population consume home-prepared rather than commercially with processed food, in contrast to Western countries such as the United States, according to Labarthe.
“Governments and health systems would benefit and would serve their beneficiaries by implementing salt substitution as an important means to reduce blood pressure and risk of stroke,” Labarthe said. “This will be impactful to the degree that individual behavior determines how much salt is consumed; it will be less so where the processed or manufactured foods predominate, until the food industry adopts the use of salt substitute in its products.”
The Salt Substitute and Stroke Study (SSaSS) was funded by grants APP1164206 and APP1049417 from the National Health and Medical Research Council of Australia.