A systematic scoping review evaluating sugar-sweetened beverage taxation from a systems perspective.
Systems thinking can reveal surprising, counterintuitive or unintended reactions to population health interventions (PHIs), yet this lens has rarely been applied to sugar-sweetened beverage (SSB) taxation. Using a systematic scoping review approach, we identified 329 papers concerning SSB taxation, of which 45 considered influences and impacts of SSB taxation jointly, involving methodological approaches that may prove promising for operationalizing a systems informed approach to PHI evaluation. Influences and impacts concerning SSB taxation may be cyclically linked, and studies that consider both enable us to identify implications beyond a predicted linear effect. Only three studies explicitly used systems thinking informed methods. Finally, we developed an illustrative, feedback-oriented conceptual framework, emphasizing the processes that could result in an SSB tax being increased, maintained, eroded or repealed over time. Such a framework could be used to synthesize evidence from non-systems informed evaluations, leading to novel research questions and further policy development.
Acknowledgements: We gratefully acknowledge I. Kuhn, who provided valuable guidance on the selection of electronic databases and respective search strategies and assistance locating full text records, and L. Garcia and P. Hovmand, who reviewed an earlier draft and provided key feedback from a systems thinking perspective. M.A., N.E., N.T.R., M.W. and J.A. are supported by the Medical Research Council (MRC) Epidemiology Unit, University of Cambridge (grant number MC/UU/00006/7). M.A. is supported by the Wellcome Trust (218629/Z/19/Z). T.P. acknowledges research support from York University. N.E. is supported by the Harding Distinguished Postgraduate Scholars Fund. L.C.-W. is a member of SPECTRUM, a UK Prevention Research Partnership Consortium. UKPRP is an initiative funded by the UK Research and Innovation Councils, the Department of Health and Social Care (England) and the UK devolved administrations and leading health research charities. The funders had no role in study design, data collection and analysis, decision to publish or preparation of the manuscript.
Funder: Removed for Double Blind Peer Review (see cover letter).