Cost effectiveness of a government supported policy strategy to decrease sodium intake: global analysis across 183 nationsBMJ 2017; 356 doi: https://doi.org/10.1136/bmj.i6699 (Published 10 January 2017) Cite this as: BMJ 2017;356:i6699
- Michael Webb, doctoral candidate1,
- Saman Fahimi2,
- Gitanjali M Singh, assistant professor3,
- Shahab Khatibzadeh, postdoctoral fellow2,
- Renata Micha, research assistant professor3,
- John Powles, honorary senior visiting fellow4,
- Dariush Mozaffarian, dean3
- 1Stanford University, Stanford, CA, USA, and Institute for Fiscal Studies, London, UK
- 2Harvard TH Chan School of Public Health, Boston, MA, USA
- 3Tufts Friedman School of Nutrition Science & Policy, 150 Harrison Ave, Boston, MA 02111, USA
- 4Cambridge Institute of Public Health, Cambridge, UK
- Correspondence to: D Mozaffarian
- Accepted 1 December 2016
Objective To quantify the cost effectiveness of a government policy combining targeted industry agreements and public education to reduce sodium intake in 183 countries worldwide.
Design Global modeling study.
Setting 183 countries.
Population Full adult population in each country.
Intervention A “soft regulation” national policy that combines targeted industry agreements, government monitoring, and public education to reduce population sodium intake, modeled on the recent successful UK program. To account for heterogeneity in efficacy across countries, a range of scenarios were evaluated, including 10%, 30%, 0.5 g/day, and 1.5 g/day sodium reductions achieved over 10 years. We characterized global sodium intakes, blood pressure levels, effects of sodium on blood pressure and of blood pressure on cardiovascular disease, and cardiovascular disease rates in 2010, each by age and sex, in 183 countries. Country specific costs of a sodium reduction policy were estimated using the World Health Organization Noncommunicable Disease Costing Tool. Country specific impacts on mortality and disability adjusted life years (DALYs) were modeled using comparative risk assessment. We only evaluated program costs, without incorporating potential healthcare savings from prevented events, to provide conservative estimates of cost effectiveness
Main outcome measure Cost effectiveness ratio, evaluated as purchasing power parity adjusted international dollars (equivalent to the country specific purchasing power of US$) per DALY saved over 10 years.
Results Worldwide, a 10% reduction in sodium consumption over 10 years within each country was projected to avert approximately 5.8 million DALYs/year related to cardiovascular diseases, at a population weighted mean cost of I$1.13 per capita over the 10 year intervention. The population weighted mean cost effectiveness ratio was approximately I$204/DALY. Across nine world regions, estimated cost effectiveness of sodium reduction was best in South Asia (I$116/DALY); across the world’s 30 most populous countries, best in Uzbekistan (I$26.08/DALY) and Myanmar (I$33.30/DALY). Cost effectiveness was lowest in Australia/New Zealand (I$880/DALY, or 0.02×gross domestic product (GDP) per capita), although still substantially better than standard thresholds for cost effective (<3.0×GDP per capita) or highly cost effective (<1.0×GDP per capita) interventions. Most (96.0%) of the world’s adult population lived in countries in which this intervention had a cost effectiveness ratio <0.1×GDP per capita, and 99.6% in countries with a cost effectiveness ratio <1.0×GDP per capita.
Conclusion A government “soft regulation” strategy combining targeted industry agreements and public education to reduce dietary sodium is projected to be highly cost effective worldwide, even without accounting for potential healthcare savings.
We thank the World Health Organization for use of the Noncommunicable Disease Costing Tool, and the Institute for Health Metrics and Evaluation for use of their cardiovascular disease DALY estimates.
Contributors: MW and DM conceptualised the study and wrote the final draft of the paper; DM also provided funding support and supervision. MW undertook the analysis and wrote the first draft of the paper. SF, GMS, SK, and RM prepared data and commented on the paper. JP commented on the paper. All authors approved the final version. MW acts as guarantor of the study.
Funding: This research was supported by the National Heart, Lung, and Blood Institute (R01 HL115189; principal investigator DM) and the National Institute of Diabetes and Digestive and Kidney Diseases (T32 training grant in academic nutrition, DK007703; GMS), National Institutes of Health. The sponsors had no role in the study design; in the collection, analysis, and interpretation of data; in the writing of the report; and in the decision to submit the article for publication.
Competing interests: All authors have completed the ICMJE uniform disclosure form at www.icmje.org/coi_disclosure.pdf and declare: financial support from the National Institutes of Health for the submitted work. DM reports ad hoc honorariums or consulting fees from Boston Heart Diagnostics, Haas Avocado Board, Astra Zeneca, GOED, DSM, and Life Sciences Research Organization, none of which were related to topics of dietary sodium. The other authors report no financial relationships with any organizations that might have an interest in the submitted work in the previous three years.
Ethical approval: Not required.
Data sharing: The global data on sodium intake may be requested from the authors for academic collaborations; see www.globaldietarydatabase.org/requesting-data.html. Global data on blood pressure is available for download at www1.imperial.ac.uk/publichealth/departments/ebs/projects/eresh/majidezzati/healthmetrics/metabolicriskfactors/metabolic_risk_factor_maps/ Global data on cardiovascular events is available for download from the Global Burden of Diseases Study at http://ghdx.healthdata.org/global-burden-disease-study-2013-gbd-2013-data-downloads.
Transparency: The lead author (MW) affirms that the manuscript is an honest, accurate, and transparent account of the study being reported; that no important aspects of the study have been omitted; and that any discrepancies from the study as planned (and, if relevant, registered) have been explained.
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