Half of trial results in ClinicalTrials.gov not published

December 3, 2013, Public Library of Science

Half of trials with results posted in ClinicalTrials.gov database have not been published in a journal, and for some that have, the database contains more information.

The trial registry ClinicalTrials.gov, which permits posting of trial results, includes results of some trials that have not been published in a peer-reviewed journal and in some cases includes more information than published trials, according to Carolina Riveros (INSERM, Paris, France) and colleagues, authors of a PLOS Medicine study published this week. The researchers searched ClinicalTrials.gov on March 2012 for of drugs with posted results. They selected 594 of these trials at random and searched PubMed for corresponding publications. Of the trials, 297 (50%) had no corresponding published article, despite the unpublished trials having a median year of completion of 2009.

Some outcomes were significantly more likely to be posted on ClinicalTrials.gov than published in the article; these were flow of participants (64% [129/202] vs. 48% [96/202] of trials, p<0.001), efficacy results (79% [159/202] vs. 69% [140/202], p=0.02), adverse events (73% [147/202] vs. 45% [91/202], p<0.001) and serious adverse events (99% [199/202] vs. 63% [127/202], p<0.001).

The authors state, "Our results have important implications for several stakeholders: patients and clinicians, authors, researchers performing systematic reviews and meta-analyses, methodologists, peer reviewers, developers of reporting guidelines and journal editors… our results outline the importance of registries to improve transparency in clinical research by making about clinical trials including results publicly available, which is the basis for well-informed decision making about patients' health."

The authors acknowledge that unpublished trial results could be published at a future date; some trials may be submitted for publication several years after completion. They conclude, "our results highlight the importance of extracting efficacy and safety data posted at ClinicalTrials.gov for trials whose results are not yet published but also for those with published results because we found that reporting was more complete at ClinicalTrials.gov. Use of templates allowing for standardized reporting of trial results in journals or broader mandatory registration of results for all may help further improve transparency."

Explore further: Clinical trial results for cancer drugs often not published

More information: Riveros C, Dechartres A, Perrodeau E, Haneef R, Boutron I, et al. (2013) Timing and Completeness of Trial Results Posted at ClinicalTrials.gov and Published in Journals. PLoS Med 10(12): e1001566. DOI: 10.1371/journal.pmed.1001566

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3 comments

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freethinking
1 / 5 (7) Dec 03, 2013
A medical gov site not working, who would have guessed.

Physorg, why no real in-depth review of the Obama website failing? Why no real in-depth review of how millions of people have lost healthcare because of Obamacare?

Is Physorg scared of the IRS or the DOJ? Or is Physorg paid to promote Obama like other medical news sites?
Sinister1811
not rated yet Dec 03, 2013
Really? Half of the results or 95% of the results not published? I had a look on there once, but couldn't find very much at all. It's an absolute joke that they do all of these trials, but don't mention anything about them anywhere. So researchers don't know what works, and what doesn't.
Sinister1811
2.5 / 5 (2) Dec 04, 2013
Is Physorg scared of the IRS or the DOJ? Or is Physorg paid to promote Obama like other medical news sites?


What does it have to do with Obama? It's got more to do with the incompetence of modern medical research, imo.

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