Appraisal of joint tobacco and alcohol tax interventions for harm reduction in the UK: the SYNTAX integrated evidence synthesis project.

BACKGROUND: Alcohol and tobacco are risk factors for non-communicable disease and deaths in England. People using both substances have increased health risks. While increasing tax on each product has been shown to reduce consumption and harm, little research has examined effects of changing both taxes together. OBJECTIVES: Work package 1: describe potential tobacco and alcohol tax policies; work package 2: analyse purchasing patterns across population subgroups; work package 3: estimate industry tax-pass-through; consumer response to price changes for 12 products; work package 4: simulate impact of 33 policy options, United Kingdom Government 2021 proposals to restructure alcohol duty and (after project end date) 2023 alcohol duty reform. DESIGN: Work package 1 reviewed literature and interviewed stakeholders to identify policy options. Work package 2 analysed repeat cross-sectional survey data on purchasing. Work package 3 used quantile regression on market research data to estimate tax pass-through and a two-stage Tobit model to estimate consumer responses (own-price and cross-price elasticities) for 12 products (beer, cider, wine, spirits and ready-to-drinks, split off-trade/on-trade; cigarettes, roll-your-own tobacco). Work package 4 developed tax modelling for the Sheffield Tobacco and Alcohol Policy Model (v2.1.0) to analyse work package 1 policy options. Later, version v2.4.2 was used to analyse emerging policy on alcohol duty reforms. SETTING: Effects of United Kingdom tax policies in England, covering 2017-50. PARTICIPANTS: Life course simulation of individuals aged 18-89; 2017-50. INTERVENTIONS: Tax policies changes: (1) specific duty per product, (2) duty escalators for alcohol and tobacco, and Minimum Excise Tax on tobacco, (3) hypothetical strength-based alcohol taxes, (4) United Kingdom Government's 2021 proposals for alcohol duty reform and (5) analysis of United Kingdom Government's implemented Alcohol Duty Reform 2023. OUTCOME MEASURES: Changes in participation in drinking or smoking, amounts consumed, expenditures, Government tax revenues, retailer revenues, risks of hospitalisation and death from over 60 clinical conditions, National Health Service secondary costs, quality-adjusted life-years, mortality and health inequalities. RESULTS: Work package 1 identified policy options. Work package 2 showed variations in expenditure by subgroup. Work package 3 showed that retailers increased prices of expensive products by more than expected after tax rises, keeping cheap product prices lower. Work package 3 showed statistically significant participation and consumption price responsiveness for all 12 products. Work package 4 compared 33 policies, showing that higher tax increases, especially for cider and hand-rolled tobacco, are effective at reducing smoking rates, drinking and deaths over 20 years. Effects were largest for people living in more deprived areas. Tailored modelling (after project end date) examined United Kingdom Government's 2023 implemented alcohol duty reform, estimating a small reduction in alcohol consumption and deaths. In contrast, a policy to increase cider taxes to be in line with beer could result in a 30 times larger reduction in deaths. LIMITATIONS: Uncertainty in estimates remains. Data used were collected pre-coronavirus disease discovered in 2019. Sales data were from legal retailers; illicit tobacco was not examined. Each sub-study has its own data limitations. CONCLUSIONS: Combined increases in tax on tobacco and alcohol could potentially be more effective at reducing disease, National Health Service costs, deaths and health inequalities than raising tax on only one product. Potential trade-offs could exist between health benefits and effects of tobacco and alcohol tax increases on financial burden for those who continue consuming both products. Future tobacco or alcohol tax analyses should factor in inter-linkages between both commodities. FUTURE WORK: We are adapting modelling infrastructure to deliver responsive within-days modelling for new government proposals and budgets. Further work on price elasticities in other countries would be useful. Future analyses will incorporate post-coronavirus disease discovered in 2019 data. We are extending modelling to other United Kingdom countries, and pricing policies beyond tax (e.g. minimum pricing). We are extending analyses to no and low alcohol products and to evaluate observed impacts of the government's alcohol duty reforms. FUNDING: This synopsis presents independent research funded by the National Institute for Health and Care Research (NIHR) Public Health Research programme as award number 16/105/26.