Population health and health sector cost impacts of the UK Soft Drinks Industry Levy: a modelling study
Authors: Cobiac Linda J , Law Cherry , Smith Richard , Cummins Steven , Rutter Harry , Rayner Mike , Mytton Oliver , Briggs Adam D M , Jensen Henning Tarp , Keogh-Brown Marcus , Adams Jean , White Martin , Scarborough Peter 
Published: October 2023

Objective

To model future impacts of the UK Soft Drinks Industry Levy (SDIL) on population health and health sector costs, and to estimate net monetary benefit to the health system.

Design

Proportional multi-state lifetable modelling study

Setting

United Kingdom

Population

All children and adults

Intervention

The SDIL is a two-tier levy of £0.18 per litre on drinks with between 5g and 8g of total sugars per 100mL, and £0.24 per litre on drinks with 8g or more of total sugars per 100mL. We estimated a per person reduction in sugar from previous interrupted time series analysis, which found an 8.0 g/household/week (95% confidence interval: 2.4 to 13.6) reduction in sugar in purchased drinks at one year after implementation.

Main outcome measures

We evaluated impact of the sugar reduction on: (a) prevalence of overweight and obesity, obesity-related diseases and dental health out to 2050; and (b) lifetime population health (measured in quality-adjusted life years [QALYs]), change in costs to the health sector and the resulting net monetary benefit.

Results

The model predicts that the SDIL will reduce prevalence of overweight and obesity in the UK by 0.18 percentage points (95% uncertainty interval: 0.059 to 0.31) for males and 0.20 percentage points (0.064 to 0.34) for females, for as long as the sugar-reduction effects of the SDIL are sustained. In the first ten years of implementation, the reductions in sugar and overweight/obesity are predicted to prevent 270,000 (35,000 to 600,000) dental caries, 12,000 (3,700 to 20,000) cases of type 2diabetes, 3,800 (1,200 to 6,700) cases of cardiovascular diseases, and 350 (110 to 590) cases of obesity-related cancer. For the current UK population, it is estimated the SDIL will add 200,000 QALYs (63,500 to 342,000) over their lifetime and avert £174 million (£53.6 to £319) in their costs of health care (discounted at UK Treasury rates). At a UK Treasury value of £60,000 per QALY, it is estimated the SDIL will produce a net monetary benefit of £12.2 billion (£3.88 to £20.8) for the health system.

Conclusion

This study of the UK SDIL tiered tax on sugar content provides further evidence that sugar- sweetened beverage taxes have the potential to achieve meaningful improvements in population health and reduce health sector spending.

What is already known on this topic

Numerous modelling studies have shown that sugar-sweetened beverage taxes are likely to be cost-effective and improve population health, whether the tax is applied on the volume of product or to the sugar content (absolute or tiered), but there have been few modelling studies that have been informed by evaluation of real-world taxes.

A volumetric sugar-sweetened beverage tax of 1 peso per litre, implemented in Mexico in 2014, reduced purchases of sugar-sweetened beverages by 7.6% in the first two years, and health economic modelling estimated that it would be cost-effective from a health sector perspective.

In the UK, the Soft Drinks Industry Levy (SDIL), announced in March 2016 and implemented in April 2018, was designed as a tiered levy to encourage soft drink manufacturers to reduce sugar content. Follow-up at one year indicates that it has reduced purchases of sugar from drinks by 8.0 g/household/week (95% confidence interval: 2.4 to 13.6).

What this study adds

Population health modelling suggests that changes in sugar consumption due to the SDIL will reduce prevalence of overweight/obesity and related diseases and improve dental health in the UK, including 12,000 (95% uncertainty interval: 3,700 to 20,000) fewer cases of type 2 diabetes, 3,800 (1,200 to 6,700) fewer cases of cardiovascular diseases, 350 (110 to 590) fewer cases of obesity-related cancer, and 270,000 (35,000 to 600,000) fewer dental caries, in the first ten years after implementation.

Health economic modelling indicates that over the lifetime of the current UK population the SDIL could add 200,000 quality-adjusted life years (63,500 to 342,000) and avert £174 million (£53.6 to £319) in health care costs, leading to a net monetary benefit of £12.2 billion (£3.88 to £20.8) for the health sector.

This study of the UK SDIL tiered tax on sugar content provides further evidence that sugar- sweetened beverage taxes have the potential to achieve meaningful improvements in population health and reduce health sector spending.