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

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.