Identifying conflict of interest disclosure in systematic reviews of surgical interventions and devices: a cross-sectional survey

Background Conflict of interest (COI) is an important source of bias in research and disclosure is the most frequent strategy to manage COI. Considering the importance of systematic reviews (SRs) and the prevalence of COI is varying among different research fields and the, we conducted a survey to identify the range of conflict of interest in SRs assessing surgical intervention and devices, and explored the association between COI disclosure and conclusion. Methods We retrieved SRs of surgical interventions and devices published in 2017 via PubMed. Information regarding general characteristics, funding source and COI disclosure were extracted. We conducted a descriptive analyses of study characteristics of included systematic reviews. The difference between groups in the authors’ conclusions were compared using the Chi-square test. Results were expressed as odds ratio and its 95% confidence interval. Results 155 SRs were finally identified in 2017, more than half of SRs (58.7%) reported their funding source and 94.2% reported authors’ COI disclosure. Among 146 SRs that stated COI disclosures, only 35 (22.6%) SRs declared at least one author had a COI. More than 40 terms were used to describe COI. Cochrane SRs were more likely to provide a detail description of COI comparing with those in non-CSR (48.0% versus 25.4%, P = 0,023). No association between positive conclusion and COI disclosure was found (P = 0.484, OR = 0.43, 95%CI: 0.08, 2.16). In the subgroup analyses, SRs stating no COI disclosure were more likely to report positive conclusion than those stating at least one type of COI, but the difference is not significantly different (P = 0.406, OR = 1.38, 95%CI: 0.64, 2.98) Conclusion A high rate of COI disclosure without any detailed information. Although little impact of COI disclosure on author’ conclusions in SRs was found for limited sample, clear description of all potential COI is the best way to enhance the credibility of published scholarship and unbiased evidence-informed decision.