Background Health inequalities pose a signficiant public health concern; over two-thirds of the world's population live in countries in which disparities have increased over the last 25 years. Equity-focused analysis is vital to understanding how interventions affect disadvantaged groups and prevent widening inequalities via intervention-generated inequalities. PROGRESS-Plus is a commonly used framework in equity-focused systematic reviews and evidence syntheses. However, it misses key aspects of disadvantage. We aimed to review the use of PROGRESS-Plus and develop a novel equity-focused framework to synthesise evidence with an equity perspective.

Method First, we re-analysed articles from the EQUALISE study, a review of interventions that increase or decrease inequalities in general practice, to explore the various domains of disadvantage examined in the included studies. We descriptively compared these domains of disadvantage with the existing PROGRESS-Plus framework domains. Then, we proposed a new framework to support equity-focused evidence synthesis. We iteratively discussed and refined the framework with our research team and collaborative networks to ensure practicality and applicability.

Results A total of 325 studies were included. The domains of disadvantage covered eleven categories: individual socioeconomic status, area-based measures, ethnicity, communication-related, age, gender, sex, lesbian, gay and other sexual identities, disability, and discrimination. The PROGRESS-Plus dimensions most assessed were sex (52%), ethnicity/race (49%), and age (44%). The PROGRESS-Plus framework missed context-specific groups, those with multiple intersecting disadvantage, and people who experience disability. Our new framework EQUALS MAP includes: Ethnicity (and culture and race); Qualifications (and other socioeconomic factors of household or individual); Underprivileged areas; Age; Lesbian, gay and other sexual identities; Sex and gender; Multiple disadvantages; Additional groups experiencing significant disadvantage; and Physical and mental disability.

Conclusion EQUALS MAP encompasses the key dimensions of health inequities whilst allowing a tailored approach to specific settings. This allows researchers to better summarise domains of disadvantage within equity-focused evidence synthesis. Such information is critical to ensure that policymakers and practitioners understand how an intervention impacts different groups. Subsequently, they can implement mitigating strategies to avoid exacerbation of inequalities. These steps are paramount to prioritise actions that narrow the health gap and prevent actions which widen inequalities.