The unpublished trial problem

© 2013 - William Reed Business Media SAS

People enter clinical trials for a variety of reasons. Subjects may volunteer because they hope to be cured of whatever ails them, or they may be altruistically hoping to advance the state of medical knowledge. Either way, they endure inconvenience at the very least, and often some degree of pain or discomfort. Whatever motivates them to participate in a study, it’s certainly not in order to let the study languish unpublished after completion. Yet, according to researchers from the University of North Carolina, that’s exactly what happens a quarter of the time.

First author Christopher Jones from Cooper Medical School of Rowan University and his colleagues collected data on clinical trials that had been registered with ClinicalTrials.gov between 2005 and 2009. They found 585 randomized trials that had included at least 500 people.

The scientists then used a variety of search techniques to match these trials with publications, including in non-peer reviewed venues like conferences. They even contacted study investigators to see whether their results had ever been published. For 250,000 trial participants, there were no results available anywhere. It was as if all those people had never been in a clinical trial at all.

It’s not clear what’s preventing these studies from being published. There is an unfortunate bias against publishing negative results, either because the investigators and their sponsors don’t like them or because journals and their readers don’t find them interesting. Jones and his colleagues were hoping to circumvent that bias by restricting their analysis to large trials that require too much expense and effort to be casually discarded. Yet a quarter of the trials still didn’t get published.

According to US Federal Policy for the Protection of Human Subjects  and the Declaration of Helsinki:

Authors have a duty to make publicly available the results of their research on human subjects and are accountable for the completeness and accuracy of their reports.

That’s certainly what volunteers expect when they agree to participate in a trial. Anything else could be considered a breech of ethics, if not of contract.

Jones CW, Handler L, Crowell KE, Keil LG, Weaver MA, & Platts-Mills TF (2013). Non-publication of large randomized clinical trials: cross sectional analysis. BMJ (Clinical research ed.), 347 PMID: 24169943.