According to a new study published in the Journal of the American Medical Association (JAMA), the results of clinical trials reported to the public are frequently inaccurate, raising questions about the accuracy of current and future trial transparency efforts.
The study, Reporting of Results in ClinicalTrials.gov and High-Impact Journals, looked at 96 different research trial results published in prestigious medical journals (impact factor greater than or equal to 10) between 2010 and 2011.
"Almost all (93) had at least one discrepancy between what was reported on the public clinical trial registry clinicaltrials.gov and what was posted in the journal article," the authors of the study wrote.
Why Results are Reported
Registering clinical trials and reporting top-line results to ClinicalTrials.gov was made mandatory following the 2007 passage of the Food and Drug Administration Amendments Act (FDAAA). The requirement followed concerns about needless duplication of clinical trials and potential safety harms to patients if they were participating in a trial unlikely to exhibit any benefit.
But if the results reported in either publicly available journals or ClinicalTrials.gov are not entirely accurate, the concern is that some patients may still be exposed to unnecessary trials.
"This study raises serious questions about the accuracy of results reporting in both clinical trial registries and publications, and the importance of consistent presentation of accurate results," said Joseph Ross, assistant professor of medicine and public health at Yale School of Medicine and a co-author of the study.
The study also raises questions about the accuracy of results published in less-prestigious journals. Studies published in journals like The Lancet and JAMA "tend to go through the most scrutiny before being published," Ross observed. Other journals aren't always as rigorous in their approach, leaving open the possibility that discrepancies may be even more pronounced in other journals.
However, Ross and his colleagues found that only six of the 96 studies contained "discordant results" significant enough to alter the interpretation of the trial. The authors were unable to determine which of the two results was correct, Ross said in an accompanying interview with JAMA.
"There were lots of end points reported in one source that weren't reported in the other," Ross remarked. Indeed, the study found that of the 2,089 secondary endpoints reported in the 96 trials, 20% were only reported on ClinicalTrials.gov, and another 50% only in journal publications.
Just 16% were described in both sources and reported the same results in both.
"There still needs to be greater efforts to ensure accurate reporting in the future," Ross concluded.