Do multiple community-based interventions on health promotion tackle health inequalities?

Previous systematic reviews of the impact of multi-component community-based health promotion interventions on reducing health inequalities by socio-economic status (SES) were restricted to physical activity and smoking behavior, and revealed limited and rather disillusioning evidence. Therefore, we conducted a comprehensive review worldwide to close this gap, including a wide range of health outcomes. The Pubmed and PsycINFO databases were screened for relevant articles published between January 1999 and August 2019, revealing 87 potentially eligible publications out of 2876 hits. In addition, three studies out of a prior review on the effectiveness of community-based interventions were reanalyzed under the new research question. After a systematic review process, 23 papers met the inclusion criteria and were included in the synthesis. More than half (56.5%) of the studies reported improvements of socially disadvantaged communities overall (i.e. reduced inequalities at the area level) in at least one health behavior and/or health status outcome. Amongst the remaining studies we found some beneficial effects in the most deprived sub-groups of residents (8.2%) and studies with no differences between intervention and control areas (34.8%). There was no evidence that any program under review resulted in an increase in health disparity. Our results confirm that community-based interventions may be reducing absolute health inequalities of deprived and disadvantaged populations, but their potential so far is not fully realized. For the future, greater attention should be paid to inequalities between sub-groups within communities when analyzing changes in health inequality over time.