Interventions for health equity with a One Health focus: a review of reviews

Introduction: The One Sustainable Health for All (OSH) Forum was launched in 2021 to promote a transdisciplinary "One Health/Planetary Health" approach in line with the 2030 Sustainable Development Goals. The "One Health" approach is a holistic and system-based approach that recognizes the interconnection between health of humans, animals and ecosystems. The OSH Forum leads thematic international working groups (IWGs), and the IWG on health equity undertook a scoping review as part of its mandate. This scoping review of reviews focused on actions to achieve health equity in the realm of One Health. The aim was to describe the types of health equity actions, to identify knowledge gaps and to recommend approaches integrating health equity and One Health. Methods: The literature search only included peer-reviewed action-focused papers. The WHO building blocks were adapted to categorize the lines of action into five key areas. Results: We analyzed 62 reviews out of 295 action-focused papers. Predominant actions were in the area of service delivery (26/62 reviews). Health equity was addressed through governance in 13 reviews, information/evidence data in 7, technologies in 11, and human resources in 5. Refugees, immigrants, and racial/ethnic minorities were the main targeted communities. The connection of health equity and One Health was not directly addressed except in two reviews. Nearly all the reviews were from high-income countries. Few studies assessed the impact of the interventions on health equity. Recurrent themes across the reviews were: the importance of addressing the social determinants of health; the need for disaggregated data; the critical role of human resources and community engagement; and the need to analyze power imbalances. Conclusion: The review highlighted a dire need for studies on the impact of interventions on health equity. Given the limited connections made between health equity and One Health, using a health equity lens to assess One Health initiatives, and vice versa, appears warranted.