These researchers developed a Markov macro-simulation model to perform epidemiological modelling and a cost-utility analysis of detailed individual-level health system cost data, in order to compare the impact of 8 sodium reduction interventions in New Zealand. Some interventions were voluntary (e.g., dietary counselling, a labelling programme and a campaign undertaken in the UK) and others were mandatory (requiring national laws for: legal limits on sodium in processed foods, a salt tax, and a “sinking lid” on the supply of salt to the New Zealand market). The largest health gain was from the potential intervention of a sinking lid in food salt released to the market to achieve an average adult intake of 2300 mg sodium/day (211,000 quality-adjusted life-years [QALYs] gained, 95% uncertainty interval: 170,000 to 255,000). This QALY benefit was followed in descending order by that from: (i) a salt tax (195,000 QALYs gained); (ii) mandatory 25% reduction in sodium levels in all processed foods (110,000); (iii) the package of interventions performed in the UK; (iv) mandatory 25% reduction in sodium levels in bread, processed meats and sauces (61,700); (v) media campaign (as per a previous UK one) (25,200); (vi) voluntary food labelling as currently used in NZ (7900); (vii) dietary counselling as currently used in NZ (200 QALYs gained). All the interventions produced net cost savings (except counselling – albeit still cost-effective). Cost savings were especially large with the sinking lid (NZ$1.1 billion, US$0.7 billion). Moreover, the salt tax would raise revenue (up to NZ$452 million/year). Health gain per person was greater for Māori (indigenous population) men and women compared to non-Māori.
