Targeting health equity through complex health interventions: Which evaluation methods and designs are used? A scoping review

Objectives: Health inequalities (HI) are systematic and avoidable disparities. While many public health interventions target HI reduction, their impact is not always evaluated. We assessed the extent to which economic indicators and methods are used to evaluate HI reduction in complex health interventions. Study design: We performed a scoping review following Arksey and O'Malley's framework. Methods: We searched PubMed, Scopus, CINAHL, EconLit, and PsycINFO for studies evaluating public health interventions aimed at reducing HI. Results: Of 490 screened articles, 19 met inclusion criteria. Most studies (n = 10) used randomised controlled trials. The predominant evaluation method was subgroup analyses based on socioeconomic categories (n = 10), followed by interaction terms (n = 5) and difference-in-differences (n = 4). However, no study directly assessed HI reduction using dedicated economic indicators. Conclusions: Despite the stated goal of reducing HI, evaluations often fail to measure this impact explicitly. This omission poses methodological risks, as some interventions may unintentionally widen disparities. We advocate for systematic inclusion of economic indicators, such as the Gini index or methods, such as Distributional Cost-Effectiveness Analysis, to ensure a more rigorous assessment of HI in public health interventions.