Influence of author's affiliation and funding sources on the results of cohort studies on occupational cancer

Background Reliability and credibility of research conducted by industry have been questioned, including in the field of occupational health. Methods Cohort studies on occupational cancer published between 2000 and 2010 were compared according to their results, their conclusions, their funding, and the affiliation of their authors. Results Overall, 510 articles were included. Studies published by authors with public affiliation or funded by public grants concluded that their study showed an excess of cancer more frequently (P = 0.01) than studies published by authors with private affiliation or funded by private grants (88% [95%CI = 85–91] vs. 73% [95%CI = 56–88] and 92% [95%CI = 86–97] vs. 71% [95%CI = 57–84], respectively). Discrepancies between statistical results and conclusion occurred more frequently in articles written by authors from the private sector than from the public sector (42% [IC95% = 26–60] vs. 23% [IC95% = 18–26], P = 0.02). Conclusions Industry affiliations of authors or industry support of studies are associated with the results of published studies on occupational cancer. The underlying mechanisms warrant further investigation. Am. J. Ind. Med. 59:221–226, 2016. © 2015 Wiley Periodicals, Inc.