P40 A meta-framework for incorporating socio-economic health inequalities in systematic reviews

Background Recent equity systematic review guidance encourages reviewers to consider whether it is likely that their findings may impact on health inequalities. Much of the guidance assumes that health inequalities have either already been identified as the focus of the review, or that reviewers are able to recognise if and how health inequalities matter. However, our experience is that this is not necessarily true. Furthermore, theorising if and how health inequalities matter is not normally integrated into the systematic review process. This presentation describes a novel approach to the development of a theory-led meta-framework to inform socio-economic health inequality considerations in systematic reviews. Methods Following the best-fit framework synthesis approach, a meta-framework was generated by ‘deconstituting’ concepts from theories relating to complex interventions and socio-economic health inequalities into a single framework. Theories were identified via; i) searches in MEDLINE, CINAHL, The Cochrane Library (CDSR, Other reviews, HTA), the Database of Promoting Health Effectiveness Reviews (DoPHER), the Campbell Collaboration Library of Systematic Reviews, 3ie (International Initiative for Impact Evaluation) database of systematic reviews, Google Scholar, Campbell and Cochrane Equity Methods Group website), ii) scanning of known relevant theoretical papers, iii) theories identified in a published work on the use of programme theory in socio-economic focused systematic reviews and iv) informal discussions with health inequality experts. Feedback was sought from health inequality experts and reviewers. Results Four complex intervention theories identify four domains and key factors that may influence effectiveness; intervention design, implementation, context and participant response. Applying an equity lens, 16 socio-economic health inequality theories identify key factors and mechanisms associated with these domains that may lead to differential effects across disadvantaged populations. Conclusion The meta-framework has the potential to i) facilitate the identification and understanding of when, why and how intervention effectiveness may be moderated by socio-economic status, ii) promote a theory-led approach to incorporating socio-economic health inequality considerations in systematic reviews iii) help reviewers identify the type of data to extract and inform a priori analysis on what factors are associated with differential effects across socio-economic groups, iv) help reviewers to decide whether it is likely that their review findings may have the potential for an intervention to indirectly widen or narrow socio-economic health inequalities, even when evidence of an impact in the primary research is lacking. The meta-framework aims to increase the usefulness of systematic reviews in informing and implementing changes to practice.