Estimated reductions in cardiovascular and gastric cancer disease burden through salt policies in England: An IMPACT NCD microsimulation study

Objective
To estimate the impact and equity of existing and potential United Kingdom salt reduction policies on primary prevention of cardiovascular disease and gastric cancer in England.

Design
A microsimulation study of a close-to-reality synthetic population. In the first period, 2003-2015, we compared the impact of current policy against a counterfactual ‘no intervention’ scenario, which assumed salt consumption persisted at 2003 levels. For 2016–2030, we assumed additional legislative policies could achieve a steeper salt decline and we compared this against the counterfactual scenario that the downward trend in salt consumption observed between 2001 and 2011 would continue up to 2030.

Setting
Synthetic population with similar characteristics to the non-institutionalised population of England.

Participants
Synthetic individuals with traits informed by the Health Survey for England.

Main measure
Cardiovascular disease and gastric cancer cases and deaths prevented or postponed, stratified by fifths of socioeconomic status using the index of multiple deprivation.

Results
Since 2003, current salt policies have prevented or postponed approximately 52,000 CVD cases (interquartile range (IQR): 34,000 to 76,000) and 10,000 CVD deaths (IQR: 3,000 to 17,000). In addition, the current policies have prevented approximately 5,000 new cases of GCa (IQR: 2,000 to 7,000) resulting in about 2,000 fewer deaths (IQR: 0 to 4,000). This policy did not reduce socioeconomic inequalities in CVD, and likely increased inequalities in gastric cancer.
Additional legislative policies from 2016 could further prevent or postpone approximately 19,000 CVD cases (IQR: 8,000 to 30,000) and 3,600 deaths by 2030 (IQR: -400 to 8,100) and may reduce inequalities. Similarly, for GCa 1,200 cases (IQR: -200 to 3,000) and 700 deaths (IQR: -900 to 2,300) could be prevented or postponed with a neutral impact on inequalities.

Conclusions
Current salt reduction policies are powerfully effective in reducing the cardiovascular and gastric cancer disease burdens overall but fail to reduce the inequalities involved. Additional structural policies could achieve further, more equitable health benefits.