Dermatology: Public Registration of Clinical Trials Helps to Address Bias

Jan 31, 2018

Doctors rely on published evidence to guide patient care decisions, and researchers use the published literature to guide which promising areas of enquiry to pursue. However, a recent study published in JAMA by Dr. An-Wen Chan and others found that half of clinical trials are never published. Even when published, many articles selectively report some results while suppressing other data.
Non-reporting of research means that this evidence is unavailable to guide patient care and future research. Since the published data are skewed towards positive results, then doctors and researchers are basing their decisions on a limited and biased subset of information. This bias leads to the use of treatments that are ineffective, unnecessarily costly, and at its worst, harmful. Biased, incomplete reporting also wastes valuable research resources and time.
To address these concerns, Dr. Chan led the WHO International Clinical Trials Registry Platform to introduce global standards for clinical trial registration in 2006. However, until the recent JAMA paper, it was unclear how often trials were being publicly registered and whether registration actually helped to reduce bias.
In this study, Dr Chan and collaborators tracked a sample of clinical trials initiated in Finland and followed them from their inception to see if they were subsequently registered or published. His team found that over a third of trials were unregistered, while a fifth of trials had different primary outcomes listed in the protocol versus the publication. Registered trials were over four times more likely to be published (adjusted OR 4.53, 95% CI 1.12 to 18.34) and over five times more likely to be published without any outcome discrepancies (adjusted OR 5.79, 95% CI 1.42 to 23.65).
These findings indicate that trial registration may help reduce biased reporting of primary outcomes in subsequent publications. However, clinical trials are often unregistered, unpublished, and discrepant in the reporting of primary outcomes across information sources. These deficiencies impair transparency and facilitate the biased reporting of trial results. Journal editors, legislators, funding agencies, regulators, research ethics committees, and sponsors should implement and enforce policies mandating registration and public access to full protocols for all clinical trials. Only with accessible, complete information can interventions be adequately evaluated for patient care.

You can read the article in its entirety here.

Chan A-W, Pello A, Kitchen J, Axentiev A, Virtanen JI, Liu A, Hemminki E. Association of Trial
Registration With Reporting of Primary Outcomes in Protocols and Publications. JAMA 2017;318:1709-11.

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