Valuing behavioural interventions for obesity reduction: A scoping review of economic models

Abstract Policymakers require health economic modelling to guide their decision-making over the choice of interventions for obesity. This scoping review was undertaken to report on the health economic models in use for estimating the value of behavioural interventions (individual or population level) for obesity reduction. Electronic databases (MEDLINE, Embase, PsycINFO, EconLit and Web of Science) were searched for publications meeting inclusion criteria from January 2015 to May 2023. Seventy-three studies were included, using 44 health economic models between them. When considered against the expert recommendations for modelling of this type, only four models (9%) met all five key elements. The element most commonly unfulfilled was the use of a microsimulation modelling approach (41%, n = 18), followed by model validation (46%, n = 20). A majority of models met each of the other elements: use of a lifetime horizon (59%, n = 26), inclusion of key health events (66%, n = 29) and a risk equation approach to event simulation (71%, n = 31). In addition, under half of the studies considered health inequalities in their reporting. Continued proliferation of models with inadequate time horizons, breadth of obesity-related health conditions, and perspectives on costs and outcomes, risks underestimation of the benefits of longer-term interventions and impacts on health inequalities.