Head-to-head randomized trials are mostly industry sponsored and almost always favor the industry sponsor

Stefania Boccia, Maria Elena Flacco, Lamberto Manzoli, Lorenzo Capasso, Annalisa Rosso, Giacomo Scaioli, Corrado De Vito, Roberta Siliquini, Paolo Villari, John P.A. Ioannidis

Research output: Contribution to journalArticlepeer-review

94 Citations (Scopus)


OBJECTIVES: To map the current status of head-to-head comparative randomized evidence and to assess whether funding may impact on trial design and results. STUDY DESIGN AND SETTING: From a 50% random sample of the randomized controlled trials (RCTs) published in journals indexed in PubMed during 2011, we selected the trials with ≥ 100 participants, evaluating the efficacy and safety of drugs, biologics, and medical devices through a head-to-head comparison. RESULTS: We analyzed 319 trials. Overall, 238,386 of the 289,718 randomized subjects (82.3%) were included in the 182 trials funded by companies. Of the 182 industry-sponsored trials, only 23 had two industry sponsors and only three involved truly antagonistic comparisons. Industry-sponsored trials were larger, more commonly registered, used more frequently noninferiority/equivalence designs, had higher citation impact, and were more likely to have "favorable" results (superiority or noninferiority/equivalence for the experimental treatment) than nonindustry-sponsored trials. Industry funding [odds ratio (OR) 2.8; 95% confidence interval (CI): 1.6, 4.7] and noninferiority/equivalence designs (OR 3.2; 95% CI: 1.5, 6.6), but not sample size, were strongly associated with "favorable" findings. Fifty-five of the 57 (96.5%) industry-funded noninferiority/equivalence trials got desirable "favorable" results. CONCLUSION: The literature of head-to-head RCTs is dominated by the industry. Industry-sponsored comparative assessments systematically yield favorable results for the sponsors, even more so when noninferiority designs are involved.
Original languageEnglish
Pages (from-to)811-820
Number of pages10
JournalJournal of Clinical Epidemiology
Publication statusPublished - 2015


  • Conflict of interest
  • Cross-sectional study
  • Head-to-head comparison
  • Industry sponsorship
  • Noninferiority trials
  • Randomized controlled trials


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