The impact of funding on the quality and interpretation of systematic reviews of mechanical thrombectomy in stroke patients.

Abstract

Funding may impact the quality and findings of systematic reviews (SRs). We aimed to compare the methodological quality of funded and non-funded SRs that investigated the outcomes in ischemic stroke patients undergoing mechanical thrombectomy. We conducted a comprehensive search strategy in different databases, including Ovid Cochrane Central Register of Controlled Trials, Ovid Embase, Ovid Medline (including epub ahead of print, in-process & other non-indexed citations), PubMed, Scopus and Web of Science Core Collection to retrieve all relevant SRs. Random sequence generation matched each funded SR with a non-funded one. A Measurement Tool to Assess Systematic Reviews (AMSTAR)-2 tool was used to assess the bias and quality of the included SRs. We also used uni- and multivariate analysis to perform our analysis, and results were expressed in odds ratio (OR) and 95% confidence interval (CI). We retrieved 150 articles, which were randomized and matched into 100 SRs, including 50 funded and 50 non-funded studies. By multivariate analysis, we found that including randomized clinical trials (RCTs) (OR: 5.7; 95% CI: 1.8-17.8; p = 0.003) and reporting conflict of interests (OR: 5.2; 95 CI: 1.1-24; p = 0.036) were the only significant differences between funded and non-funded SRs. No significant differences were found regarding the overall confidence for low-quality (OR: 0.54; 95% CI: 0.09-3.2; p = 0.49) and moderate/high-quality SRs (OR: 0.17; 95% CI: 0.02-1.87; p = 0.14). Funded studies tend to include RCTs more often and report conflict of interests with no significant impact on overall confidence.