Yale School of Medicine researchers have found that less than half of a sample of trials primarily or partially funded by the National Institutes of Health (NIH) were published within 30 months of completing the clinical trial. The findings appear in the British Medical Journal.

"When research findings are not disseminated, the scientific process is disrupted and leads to redundant efforts and misconceptions about clinical evidence," says Joseph Ross, MD, first author of the study and assistant professor of medicine at Yale. "Such inaction undermines both the trial in question and the evidence available in peer-reviewed medical literature. This has far-reaching implications for policy decisions, and even institutional review board assessments of risks and benefits associated with future research studies."

The researchers performed a cross-sectional analysis of NIH-funded clinical trials registered within ClinicalTrials.gov, a trial registry and results database maintained by the US National Library of Medicine. All trials in the study sample were registered after September 30, 2005, and completed by December 31, 2008, allowing at least 30 months for publication following completion of the trial.

They found that overall less than half of NIH-funded trials in the sample were published in a peer-reviewed, MEDLINE-indexed biomedical journal within 30 months of trial completion. They also found that one-third of trials remained unpublished 51 months after completion.

Ross says that there may be many reasons for lack of publication, such as not getting accepted by a journal or not prioritizing the dissemination of research findings. Still, he points out, there are alternative methods for providing timely public access to study results, including the results database at ClinicalTrials.gov that was created in response to federal law.

While this study was focused on trials funded by NIH, Ross said that similar problems with nonpublication and delayed publication of research findings have been described among trials funded by the pharmaceutical and medical device industries, as well as by nonprofit organizations.

"This suggests that the current culture of research needs to prioritize the timely public dissemination of research findings, ideally via peer-reviewed journals, for research funded by both public and private sources," said Ross. "More work needs to be done to better understand impediments to publication."

Source: Yale University