Annals of Internal Medicine
March 1, 2010
Background: Sodium consumption raises blood pressure, increasing the risk for heart attack and stroke. Several countries, including the United States, are considering strategies to decrease population sodium intake.
Objective: To assess the cost-effectiveness of 2 population strategies to reduce sodium intake: government collaboration with food manufacturers to voluntarily cut sodium in processed foods, modeled on the United Kingdom experience, and a sodium tax.
Design: A Markov model was constructed with 4 health states: well, acute myocardial infarction (MI), acute stroke, and history of MI or stroke.
Data Sources: Medical Panel Expenditure Survey (2006), Framingham Heart Study (1980 to 2003), Dietary Approaches to Stop Hypertension trial, and other published data.
Target Population: U.S. adults aged 40 to 85 years.
Time Horizon: Lifetime.
Outcome Measures: Incremental costs (2008 U.S. dollars), quality-adjusted life-years (QALYs), and MIs and strokes averted.
Results of Base-case Analysis: Collaboration with industry that decreases mean population sodium intake by 9.5% averts 513 885 strokes and 480 358 MIs over the lifetime of adults aged 40 to 85 years who are alive today compared with the status quo, increasing QALYs by 2.1 million and saving $32.1 billion in medical costs. A tax on sodium that decreases population sodium intake by 6% increases QALYs by 1.3 million and saves $22.4 billion over the same period.
Results of Sensitivity Analysis: Results are sensitive to the assumption that consumers have no disutility with modest reductions in sodium intake.
Limitation: Efforts to reduce population sodium intake could result in other dietary changes that are difficult to predict.
Conclusion: Strategies to reduce sodium intake on a population level in the United States are likely to substantially reduce stroke and MI incidence, which would save billions of dollars in medical expenses.
Primary Funding Source: Department of Veterans Affairs, Stanford University, and the National Science Foundation.