BackgroundFinancial 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.MethodsA 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.ResultsOf 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.ConclusionThe 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. (shrink)