Dr. Joseph Ross, an assistant professor of medicine at Yale School of Medicine, and co-authors performed a cross-sectional analysis of NIH-funded clinical trials registered within ClinicalTrials.gov, a trial registry and results database maintained by the U.S. National Library of Medicine.
All trials in the study sample were registered after Sept. 30, 2005, and completed by Dec. 31, 2008, allowing at least 30 months for publication following completion of the trial, Ross said.
The study, published in the British Medical Journal, found that overall fewer 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. The study also found one-third of the trials remained unpublished 51 months after completion.
Ross said 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, but there are alternative methods for providing timely public access to study results, including the results database at ClinicalTrials.gov.
"Steps must be taken to ensure the timely dissemination of publicly funded research so that data from all those who volunteer are available to inform future research and practice," Ross said in a statement.