Influence of Disclosed and Undisclosed Funding Sources in Tobacco Harm Reduction Discourse: A Social Network Analysis.

Introduction: Tobacco harm reduction (THR) discourse has been divisive for the tobacco control community, partially because it sometimes aligns public health and tobacco industry interests. Industry funding is contentious as it influences study outcomes, and is not always disclosed in scientific publications. This study examines the role of disclosed and undisclosed industry support on THR publications via social network analysis.

Methods: We reviewed 826 English-language manuscripts (1992-2016) to determine disclosed and undisclosed industry (pharmaceutical, tobacco, and e-cigarette) and non-industry (including government) support received by 1405 authors. We used social network analysis to identify the most influential authors in THR discourse by assessing the number of their collaborators on publications, the frequency of connecting other authors in the network, and tendency to form groups based on the presence of sponsorship disclosures, sources of funding, and THR stance.

Results: About 284 (20%) out of 1405 authors were supported by industry. Industry-sponsored authors were more central and influential in the network: with twice as many publications (Median = 4), 1.25 as many collaborators on publications (Median = 5), and higher likelihood of connecting other authors and thus having more influence in the network, compared to non-industry-sponsored authors. E-cigarette industry-sponsored authors had the strongest association with undisclosed industry support.

Conclusions: Authors with industry support exerted a stronger influence on the THR scientific discourse than non-industry-supported authors. Journals should continue adhering to strict policies requiring conflicts of interest disclosures. An increase in public health spending on tobacco control research may be necessary to achieve funding parity.