Tag Archives: Clinial Trial Bias

More trials with favorable outcomes get published

An observational study published in PLoS Medicine finds that not all trial results in New Drug Applications for new drugs submitted to the FDA are published in medical journals. Researchers from the University of California, San Francisco, examined efficacy trials between 2001 and 2002, and searched for discrepancies between trial data included in NDAs and in published articles between July 2006 and June 2007.

New drug applications, from the FDA

New drug applications

They found that “only three-quarters of the efficacy trials in the NDAs were published; trials with favorable outcomes were nearly five times as likely to be published as those without favorable outcomes. Although 155 primary outcomes were in both the papers and NDAs, 41 outcomes were only in the NDAs.

Just the same, they offered some optimism: “The recent introduction in the US and elsewhere of mandatory registration of all clinical trials before they start and of mandatory publication in trial registers of the full results of all the predefined primary outcomes should reduce publication bias over the next few years and should allow clinicians and patients to make fully informed treatment decisions.”

But in an accompanying editorial, An-Wen Chan, who previously worked as a scientist with the World Health Organization’s International Clinical Trials Registry Platform and is now at the Mayo Clinic, writes that “much remains to be done – not only to establish reliable, comprehensive registration and results disclosure processes worldwide, but also to start heeding the calls for increased access to full protocols and regulatory agency submissions….”