What happens after large clinical trials are completed? Alarmingly, a new study, published in the British Medical Journal (BMJ), found that almost one in three (29%) large clinical trials remain unpublished five years after completion. The non-publication of trial data “violates an ethical obligation that investigators have towards study participants,” the study authors, led by Christopher W. Jones, MD, an attending physician in the department of emergency medicine at Cooper Medical School of Rowan University, wrote.
For this study, investigators identified all trials with at least 500 participants that were prospectively registered with ClinicalTrials.gov and completed prior to January 2009. They then completed literature searches between April and November 2012. to see which of these trials had published results after completion. From the 585 registered trials, Dr. Jones and colleagues found that 171 (29%) remained unpublished — comprising an estimated 299, 763 study participants. Of the 171 unpublished trials, 133 (78%) had no publicly available results.
The authors identified that trials supported by the National Institutes of Health or other federal sources were less likely to remain unpublished compared with those without federal funding (17% v 31%, P=0.025). However, those trials funded by industry were more likely to be remain unpublished (150/468, 32%), compared with those that were not industry funded (21/117, 18%), P=0.003.
“A substantial number of study participants were exposed to the risks of trial participation without the societal benefits that accompany the dissemination of trial results,” wrote Dr. Jones and investigators. They suggest that increased institutional review board attention towards this persistent problem of unpublished trial data may be necessary.
Stay tuned for a full report on this study in an upcoming issue of Neurology Today. See our previous coverage of ethical conduct in clinical trials: http://bit.ly/16siZrc.