Background This systematic review aims to estimate the proportion of medical schools and teaching hospitals with conflicts of interest (COI) policies for health research and education, to describe the provisions included in the policies and their impact on research outputs and educational quality or content.Methods Experimental and observational studies reporting at least one of the above mentioned aims were included irrespective of language, publication type or geographical setting. MEDLINE, Scopus, Embase and the Cochrane Methodology Register were searched from inception to March ۲۰۲۰. Methodological study quality was assessed using an amended version of the Joanna Briggs Institute’s checklist for prevalence studies. Results Twenty-two cross-sectional studies were included; all were conducted in high-income countries. Of these, ۲۰ studies estimated the prevalence of COI policies, which ranged from ۵% to ۱۰۰% (median: ۸۵%). Twenty studies assessed the provisions included in COI policies with different assessment methods. Of these, nine analysed the strength of the content of medical schools’ COI policies using various assessment tools that looked at a range of policy domains. The mean standardised summary score of policy strength ranged from ۲% to ۷۳% (median: ۳۰%), with a low score indicating a weak policy. North American institutions more frequently had COI policies and their content was rated as stronger than policies from European institutions. None of the included studies assessed the impact of COI policies on research outputs or educational quality or content. Conclusion Prevalence of COI policies at medical schools and teaching hospitals varied greatly in high-income countries. No studies estimated the prevalence of policies in low to middle-income countries. The content of COI policies varied widely and while most European institutions ranked poorly, in North America more medical schools had strong policies. No studies were identified on impact of COI policies on research outputs and educational quality or content.
