Economic Evaluations of Obesity-Targeted Sugar-Sweetened Beverage (SSB) Taxes-A Review to Identify Methodological Issues.

Introduction: Economic evaluations of public health interventions like sugar-sweetened beverage (SSB) taxes face difficulties similar to those previously identified in other public health areas. This stems from challenges in accurately attributing effects, capturing outcomes and costs beyond health, and integrating equity effects. This review examines how these challenges were addressed in economic evaluations of SSB taxes.

Methods: A systematic review was conducted to identify economic evaluations of SSB taxes focused on addressing obesity in adults, published up to February 2021. The methodological challenges examined include measuring effects, valuing outcomes, assessing costs, and incorporating equity.

Results: Fourteen economic evaluations of SSB taxes were identified. Across these evaluations, estimating SSB tax effects was uncertain due to a reliance on indirect evidence that was less robust than evidence from randomised controlled trials. Health outcomes, like quality-adjusted life years, along with a healthcare system perspective for costs, dominated the evaluations of SSB taxes, with a limited focus on broader non-health consequences. Equity analyses were common but employed significantly different approaches and exhibited varying degrees of quality.

Conclusion: Addressing the methodological challenges remains an issue for economic evaluations of public health interventions like SSB taxes, suggesting the need for increased attention on those issues in future studies. Dedicated methodological guidelines, in particular addressing the measurement of effect and incorporation of equity impacts, are warranted.