The potential health impact and healthcare cost savings of different sodium reduction strategies in Canada

Background High dietary sodium is the main dietary risk factor for non-communicable diseases due to its impact on cardiovascular diseases, the leading cause of death globally. The Government of Canada has taken measures to reduce average dietary sodium intakes, such as setting voluntary sodium reduction targets for packaged foods and recently approving regulations mandating ‘high in’ front-of-pack labeling (FOPL) symbols. Objectives To estimate the number of avoidable ischemic heart disease (IHD) and stroke incidence cases, and their associated healthcare cost and Quality-Adjusted Life Year (QALY) savings resulting from different sodium reduction strategies and recommendations in Canada. Methods We used the PRIMEtime model, a proportional multi-state lifetable model. Outcomes were modeled over the lifetime of the population alive in 2019, at a 1.5% discount rate, and from the public healthcare system perspective. Nationally representative data were used as inputs for the model. Results Fully meeting Health Canada’s sodium reduction targets was estimated to prevent 219,490 (95% UI, 73,409–408,630) cases of IHD, and 164,435 (95% UI, 56,121–305,770) strokes. This led to a gain of 276,185 (95% UI, 85,414–552,616) QALYs, and healthcare costs savings of CAD$ 4,212(95% UI, 1,303–8,206) million over the lifetime of the 2019 cohort. Sodium reduction intake through FOPL regulations has the potential to prevent between 35,930 (95% UI, 8,058– 80,528) and 124,744 (95% UI, 40,125–235,643) cases of IHD, and between 26,869 (95% UI, 5,235–61,621) and 93,129 (95% UI, 30,296–176,014) strokes. This results in QALY gains ranging from 45,492 (95% UI, 10,281–106,579) to 157,628 (95% UI, 46,701–320,622), and healthcare costs savings ranging from CAD$ 695 (95% UI, 160–1,580) to CAD$ 2,415 (95% UI, 722–4,746) million over the lifetime of the 2019 Canadian cohort. Greater health and healthcare costs gains were estimated if Canadians were to meet the population-level sodium intake recommendations of the World Health Organization (2,000 mg/day) and the Adequate Intake recommendation (1,500 mg/day). All sodium reduction strategies tested were cost saving. Conclusions Reducing population-level sodium intakes is feasible and has the potential to improve health outcomes and save healthcare costs in Canada. From interventions tested, most health and healthcare costs gains were attributed to fully meeting sodium reduction targets, which highlights the importance of changing the voluntary nature of these targets to mandatory. A combination of strategies, mandatory sodium reduction targets and implementation of the ‘high in’ FOPL symbol would provide the most benefit from a public health standpoint. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This research was funded by Canadian Institutes of Health Research (CIHR) operating grants (PJT-165858 SA2-152805 Healthy Cities Training Award). . The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: This research did not need IRB approval I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes Analytic code (R) can be made available to researchers upon request to the author. Canadian Community Health Survey-Nutrition 2015 Public Use Microdata File (PUMF) data is publicly and freely available without restriction at Statistics Canada, Canadian population demographics, healthcare costs and epidemiology data associated with ischemic heart disease and stroke were obtained from publicly available sources – also detailed in the main manuscript.