Comparing the clinical trial characteristics of industry-funded trials and non–industry-funded trials

Importance In randomized controlled trials (RCTs), small sample size and lack of blinding can cause biased and spurious results. Whether and how study characteristics differ based on a trial’s funder is an important area to study. Objective To compare study characteristics of RCTs funded by industry with study characteristics of RCTs not funded by industry. Design, Setting and Participants We systematically reviewed all RCTs published between 2015 and 2019 in the New England Journal of Medicine (NEJM), Lancet, and Journal of the American Medical Association (JAMA). Our primary data sources were [ClinicalTrials.gov][1] and MEDLINE. Data extraction included manual review and use of natural language processing. Main Outcomes and Measures We compared the rate of blinding, use of placebo, and sample size. We used natural language processing to analyze the sentiment of the study’s conclusion as reported in the abstract. As proxies for knowledge dissemination, we calculated the AltMetric scores and number of times the article was cited (citation count). Results We identified 1533 RCTs published by NEJM, Lancet, and JAMA between 2015 and 2019. Of these RCTs, 697 were funded by industry. Trials funded by industry were more likely to be blinded (n=378, 54% vs n=318, 38%), more likely to include a placebo (n=317, 45% vs n=196, 23%), more likely to post their results on [ClinicalTrials.gov][1] (78%, 443 of 570 vs 41%, 207 of 501) compared to trials that were not industry funded. Industry-funded RCTs had a smaller sample size than non–industry-funded RCTs (median=557 [IQR: 230, 1369] vs 648 [IQR: 301, 1916], P<0.01). Trials funded by industry had more citations than non–industry-funded trials (285 vs 145, p < 0.01), while per-manuscript Almetric scores were similar between both groups (229 vs 226, p=0.2). Conclusions and Relevance These data highlight important variability in key metrics of trial quality and call attention to specific areas of improvement, especially for non–industry-funded trials. ### Competing Interest Statement MF has received multiple grants from CIHR for investigator initiated clinical trials and is a consultant for ProofDx, a start-up company that has created a point-of-care diagnostic test for COVID-19 using CRISPR. ### Funding Statement This study was funded by Mount Sinai Hospital Department of Medicine Research Fund. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All data produced in the present study are available upon reasonable request to the authors. [1]: http://ClinicalTrials.gov