Background And Objective: Inadequate competing interest declarations present interpretive challenges for editors, reviewers, and readers. We systematically studied a common euphemism, 'unpaid consultant,' to determine its occurrence in declarations and its association with vested interests, authors, and journals.
Methods: We used Google Scholar, a search engine that routinely includes disclosures, to identify 1164 occurrences and 787 unique biomedical journal publications between 1994 and 2014 that included one or more authors declaring themselves as an "unpaid consultant.