Abstract
BACKGROUND: Financial interactions between pharmaceutical companies and physicians lead to conflicts of interest. This study examines the extent and trends of non-research payments made by pharmaceutical companies to board-certified allergists in Japan between 2016 and 2020. METHODS: A retrospective analysis of disclosed payment data from pharmaceutical companies affiliated with the Japanese Pharmaceutical Manufacturers Association was conducted. The study focused on non-research payments for lecturing, consulting, and manuscript drafting made to board-certified allergists from 2016 to 2020. We performed descriptive analyses on payment data. Trends were analyzed using generalized estimating equation models. RESULTS: Of the 3,943 board-certified allergists, 2,398 (60.8%) received non-research payments totaling $43.4 million over five years. Lecturing fees comprised 85.7% ($37.2 million) of the total payment amounts. For allergists who received at least one payment, the median amount per allergist was $3,106 (interquartile range: $966 - $12,124), in contrast to a mean of $18,092 (standard deviation: $49,233) over the five-year span. The top 1% and 10% of these allergists accounted for 20.8% and 68.8% of all non-research payments, respectively. The annual payment amounts significantly increased by 7.2% annual increase (95% CI: 4.4 - 10.0%, p < 0.001) each year until 2019, but saw a significant decrease in 2020 amid the COVID-19 pandemic. CONCLUSION: The majority of allergists received non-research payments, with a notable concentration among a small group. Payments increased annually until the pandemic's onset, which coincided with a substantial decrease. Further research is needed to explore the implications of these financial interactions on clinical practice and patient care in Japan.