Data collection and coding
We retrieved the names and affiliated hospitals of all board-certified allergists from the Japanese Society of Allergology’s website. Following this, we compiled the non-research payments made for lecturing, consulting, and drafting services to these allergists by JPMA-affiliated companies from 2016 to 2020, in line with methodologies used in prior studies[28-30]. Instances of allergists with identical names were resolved by manual searches via Google and verification through official hospital and organizational websites, as previously described.[30,31] We excluded payments to individuals who could not be verified as board-certified allergists or were confirmed as ineligible physicians through our search process from our study samples.