Financial conflicts of interest among authors of clinical practice guideline for headache disorders in Japan.

Background: Financial relationships between clinical guideline authors and pharmaceutical companies introduce conflicts of interest (COI), potentially biasing guideline recommendations. Thus, proper management of COI is paramount for clinical guideline authors. Nevertheless, little is known about COI among neurology clinical guideline authors. This study aimed to evaluate the financial relationships between pharmaceutical companies and authors of Clinical Practice Guideline for Headache Disorders (CPGHD) in Japan.

Methods: This is a retrospective analysis of 2016-2020 personal payments data disclosed by all pharmaceutical companies affiliated with the Japan Pharmaceutical Manufacturers Association. We examined amounts and fraction of personal payments to all 57 CPGHD authors and all neurologists board-certified by the Japanese Society of Neurology. Payment data was descriptively analyzed at individual author level.

Results: Among 57 CPGHD authors, 56 (98.3%) received personal payments totaling $2.7 million from pharmaceutical companies between 2016 and 2020. Median five-year payments were $89,955 for CPGHD authors, while $521 for board-certified neurologists. The CPGHD chairperson and vice chairperson received substantial payments during the guideline development period. Nevertheless, because of less rigorous and transparent COI policy compared to international standard policies, only 10 authors disclosed their financial relationships with the pharmaceutical companies in the guideline.

Conclusions: More than 98% of CPGHD authors received much higher personal payments from pharmaceutical companies than those to board-certified neurologists during the guideline development period in Japan.