Study: Registration data still incomplete
While the informational quality of internationally registered trials has increased, there’s still room for improvement, according to a recent study.
The study, published in the Jan. 10, 2014, issue of PLOS One and a repeat of 2009 study from the same authors, looked at a random sample of 400 trials listed on the World Health Organization’s International Clinical Trials Registry Platform (ICTRP) between Jan. 1, 2012, and Jan. 1, 2013. The study assessed information on contact details, interventions, and primary outcomes. Evaluation of registered intervention data was limited to studies on drugs, biologics, or vaccines.1
The study described the following improvements from the 2009 analysis:
• The number of registrations that included a phone number or email address is 74.9%, up from 68.7% in 2009.
• 51.9% were complete in registering intervention specifics, up from 44.2%
• 57.6% has primary outcomes that were specific measures with a meaningful timeframe, a significant increase from the previous 38.2%.
• A contact name appeared on 85.5% of studies, up slightly from 81%.
• Half of all trials continue to be retrospectively registered, the authors wrote.1
Despite these improvements, "important problems with quality remain and continue to constitute an impediment to the meaningful utilization of registered trial information," according to the authors. While 85.5% of studies listed a contact name, there were still many that did not. Contact information is also absent, in many cases removed after completion of the trial. "Explicit mentioning of the name of the principal investigator is important to increase the accountability of trialists," the authors wrote. "To allow patients, healthcare workers and other researchers to inform themselves of clinical trials, it is important that trialists can be contacted at any stage of a trial. Such information should remain available after a trial is completed or stopped."1
Retrospective registration is also a continued problem, according to the authors. "Without prospective registration, before enrollment of the first participant, we cannot be certain that trial outcomes are not retrospectively registered in such a way that favors a particular result," they wrote.1
Quality of registered trial data likely varies due to differences in requirements and quality control among the different clinical trial registries, the authors suggested. "For example, some registries specifically ask trialists for the methods of measurement for each outcome. Others have only free text fields for outcomes. Some registries ask for specific details on interventions, others, again, have only free text fields," they wrote. "More effort needs to be made to improve data recording formats, enhance quality control measures and scale up enforcement of trial registration."1
- Viergever RF, Karam G, Reis A, Ghersi D (2014) The Quality of Registration of Clinical Trials: Still a Problem. PLoS ONE 9(1): e84727. doi: 10.1371/journal.pone.0084727.