Association between research sponsorship and study outcome in plastic surgery literature

Financial and other competing interests have recently received increasing attention. In particular clinical research in plastic surgery attracts for-profit organizations, thus, explaining the increasing number of financial sponsorships. However, research articles often lack sufficient description of study design as well as disclosure of the source of funding. Furthermore, debate exists whether industry funding influences research findings and is leading to pro-industry results. A hand search was conducted identifying all randomized controlled (RCT) and controlled clinical trials (CCT) in 4 plastic surgery journals (Plastic and Reconstructive Surgery, British Journal of Plastic Surgery, Annals of Plastic Surgery, and Aesthetic Plastic Surgery) between 1990 and 2005. Subsequently, the influence of financial support on study outcome was analyzed. A total of 10,476 original articles were analyzed, resulting in the identification of 346 clinical trials which meet the Cochrane criteria for RCTs and CCTs. One hundred eighty-three trials and 163 studies were found to be RCTs and CCTs, respectively. Hereof, only 70 trials (20.2%) reported on grant support. Of these, 42 trials (60%) were supported by the industry. Depending on the topic addressed marked differences were detected regarding grant support. Studies with a focus on reconstructive plastic surgery were supported by the industry and by public institutions in almost equal shares (18 trials vs. 15 trials), whereas aesthetic surgical topics were predominantly funded by the industry (13 trials vs. 6 trials). Industry-funded trials reported more often statistically significant differences between treatment arms (28 trials vs. 16 trials). Authors' conclusions were found to be positively associated with financial competing interests. However, trial funding is rarely declared in the plastic surgery literature. Thus, the quality of reporting needs to be improved to be able to investigate these relationships in greater detail and draw more representative conclusions.