However, clinical trials are also required to report their results on ClinicalTrials.gov. These authors review one year’s worth of clinical trials published in the three aforementioned journals and compared the high-impact results with those stashed away on ClinicalTrials.gov. Of 91 trials identified, 156 primary and co-primary endpoints were identified, but only 132 were described in both sources – and only 61% were concordant between each source. Of 2,089 secondary endpoints, 619 were described in both sources – and were only 55% concordant.
Furthermore, the authors identified six studies with primary outcomes noted on ClinicalTrials.gov resulting in alternative trial interpretation. These included changes in disease resolution or progression time, as well as results that achieved statistical significance in publication, but not on ClinicalTrials.gov.
The authors conclude:
“…possible explanations include reporting and typographical errors as well as changes made during the course of the peer review process …. journal space limitations and intentional dissemination of more favorable end points and results in publications."We ought to expect better vetting of results by journal editors – particularly from sources frequently followed by the lay media.
“Reporting of Results in ClinicalTrials.gov and High-Impact Journals”