Evidence to inform intersectoral policies: A comparison of health and transport sector evidence in support of road traffic injury prevention

Background: Health is influenced by determinants beyond the traditional conception of the health sector. Increasingly, global actors are targeting policymakers at global and national levels to take an intersectoral approach to health issues. Multilateral organizations in the health and transport communities have published policy reports targeting policymakers to address the burden of road traffic injuries. However, these reports stem from sectors grounded in different disciplinary perspectives. We investigate whether sectors have differing evidentiary traditions by analyzing differences regarding author networks, type of evidence cited, recommendations, and indicators. Methods: We selected global policy reports on road traffic injury prevention based upon expert opinion and categorized them by sector according to their institutional publisher. For each report, we i) conducted an authorship analysis by sectoral affiliation; ii) analyzed the types of research evidence cited and categorized the evidence type and institutional nature of the publisher; iii) analyzed key recommendations by extracting recommendations presented in the concluding sections of the documents; and iv) examined the use of indicators. Descriptive statistics were used to determine whether dimensions differed by the sectoral affiliation of the policy report. Results: Authorship was dominated by the sector from which the report was published, while reports that involved both sectors often showed clustering of authors in one sector or another, depending on the subject addressed. Reports originating from different sectors preferentially cited different types of evidence; notably, health sector reports emphasized observational studies and reviews, while transport sector reports drew heavily on government agency reports. There were no differences in recommendations and indicators used. Conclusions: Notions of knowledge validity and valuations of evidence vary depending on the field's historical development. Such differences in valuing evidence within sectors may have the potential to undermine the application of evidence in intersectoral policymaking. Strategies to address this challenge include the identification of key individuals to connect separate sectors, knowledge translation activities that take account of sectoral differences, and the tailoring of messages to different audiences. Future analyses on other intersectoral issues may provide clarity on points of tension and differing types of evidence used in intersectoral work.