Limitations
This study included several limitations. First, there would be underestimated payments made by non-member companies of JPMA to the otorhinolaryngologists. However, as the member companies accounted for 80.8% of total pharmaceutical sales in Japan in 2018,[1] such underestimation of payments could be minimized by including data from all member companies. Second, the pharmaceutical companies were not required to disclose other categories of payments such as meals, beverages, travel, and stock ownerships at an individual level, according to the JPMA guidance.[3] This could have led to underestimations of the extent and prevalence of overall financial relationships between otorhinolaryngologists and industries. Third, this study included otorhinolaryngologists as of November 2021, as the JSO-HNS did not disclose the name list of otorhinolaryngologists for previous years. Therefore, this study would have included otorhinolaryngologists who were not certified during the study period. Fourth, the payment magnitude and trend may not be applicable to other countries.