Background: Systematic reviews of interventions often fail to adequately consider equity. This impairs their ability to inform policy and practice decisions that aim to account for differential impacts. Central to this issue is how the dimensions of equity impacts (e.g., socioeconomic status) are conceptualised, as this shapes how equity is treated in the conduct and reporting of reviews.
Objectives: To describe the methods and frameworks (e.g., PROGRESS-Plus) used in systematic reviews to conceptualise the dimensions of equity impacts of public health interventions and issues encountered in their application. This complements a Cochrane review (Welch 2022) that surveyed the descriptive and analytic methods used to investigate health equity via PROGRESS-Plus.
Methods: Umbrella review of systematic reviews that include a focus on equity impacts of public health interventions. We used electronic database searches supplemented with automated searches of the OpenAlex dataset. An active learning algorithm was used to prioritise title-abstract records for manual screening. We extracted data from a purposively selected sample of reviews.
Results: We manually screened 2,060 prioritised title-abstract records, from which 322 full-text reports were assessed. We included 120 reports of systematic reviews. PROGRESS-Plus was the only formal method used for conceptualising dimensions of equity impacts, although most reviews that did not use it used equivalent dimensions (68/75 (91%)). Where intended methods were unable to be applied fully, this was usually because primary research studies did not report the necessary information (55/68 (81%)). Most reviews (87/120 (73%)) included an explicit rationale for focusing on equity impacts in general, but only 7% (8/120) justified their focus on (or exclusion of) specific dimensions. Authors highlighted challenges with applying these methods, including investigating constructs, such as socioeconomic status, that lack standardised operationalisation and measurement.
Conclusions: PROGRESS-Plus is the predominant method for conceptualising dimensions of equity impacts of public health interventions and mostly appears to be sufficiently comprehensive to encompass the scope of such investigations. However, significant practical and conceptual challenges need to be addressed if reviews assessing these impacts are to more meaningfully contribute to cumulative and useful evidence bases. Patient, public, and/or healthcare consumer involvement: None, but can contribute to more robust evidence production.