Financial conflicts of interest among authors of clinical practice guideline for diabetes mellitus in Japan between 2016 and 2020

Abstract Aims: To assess the financial relationships between pharmaceutical companies and authors of the Japanese Clinical Practice Guideline for Diabetes 2019. Methods: Retrospective analysis of publicly available pharmaceutical-industry personal payments evaluated size and prevalence of financial relationships between all 27 authors of the CPG and pharmaceutical companies in Japan. Personal payments from pharmaceutical companies to the authors between 2016 and 2020 were extracted from publicly disclosed database and each pharmaceutical company. Results: Of all 135 authors of clinical practice guideline for diabetes mellitus developed by the Japan Diabetes Society in 2019, 129 (95.6%) received personal payments from pharmaceutical companies between 2016 and 2020. The total amounts of personal payments were $23,130,423, with a median of $89,955 and an average of $171,336 per author. More than 74.1% (100 authors), 60.7% (82 authors), and 47.4% (64 authors) received more than $10,000, $50,000, and $100,000 personal payments in total over the five years, respectively. The guideline chairpersons of the guideline development and review committees received substantial amounts of personal payments from the companies during the guideline development period. Conclusion: Nearly all guideline authors received substantial amounts of personal payments from pharmaceutical companies during the guideline development period and one year after its publication. Nevertheless, the Japan Diabetes Society roughly managed their COIs, and many authors self-declared no financial COIs with pharmaceutical companies even though they received moderate amounts of personal payments. These findings underscore the urgent need for policy interventions to enhance transparency, integrity, and reliability in the development of clinical practice guidelines in Japan.