Transdisciplinary research for complex One Health issues: a scoping review of key concepts.

In order to address the complexity inherent in researching One Health (OH) issues, we support the concept that researchers must transcend individual disciplinary and non-disciplinary boundaries, and move into the realm of transdisciplinary (TD) research approaches. For the purposes of this paper we use the term OH and the concept that OH research is conducted to solve complex health challenges at the animal-human--human-ecosystem interface. TD goes beyond interdisciplinary research to engages disciplines and communities through a unified conceptual framework. In this scoping review we investigated key concepts, definitions and themes in OH and TD based on the peer reviewed literature. We identified nine emerging themes in TD research: (1) education, (2) conflict amongst disciplines, (3) effective communication, (4) shared conceptual framework, (5) leadership, (6) perceived power differentials, (7) community-based methodologies, (8) support for TD research and (9) time and effort. This review provides a synthesized knowledge base that describes the nature, extent of evidence and challenges of engaging in TD initiatives. This knowledge base further provides a foundation for those interested in developing improved strategies for TD collaborative and cross-sectoral research in OH.