Missing Medical Data Could Harm Patients | Observations, Scientific American Blog Network

"Big clinical trials —to test new drugs or procedures— generate reams of important data about safety and efficacy. Only a fraction of that information sees the light of day, a publishing practice that could put patients at risk, according to a special report published this week in the British Medical Journal (BMJ)....“[T]he overall result is that the published literature tends to overestimate the efficacy and underestimate the harms of a given intervention,” noted [An-Wen Chan, of the University of Toronto’s Women’s College Research Institute]....It can be difficult to get a journal to publish —or a drug company to support publication of— harmful —or null, i.e. “negative”– results from a trial. But, as that paper’s authors noted, “when unfavorable results of drug trails are not published, meta-analyses and systematic reviews that are based only on published data may overestimate the efficacy of the drugs.” ...In an editorial in the same issue of BMJ, Richard Lehman, of the University of Oxford, and Elizabeth Loder, an epidemiology editor at the journal, called for reform of the “current culture of haphazard publication and incomplete data disclosure.” They advocated for a retroactive disclosure of all clinical trial data....The U.S. government has taken a step toward making more of this data public, requiring publicly funded trials to publish full data sets within a certain time frame. But according to new findings from Joseph Ross, of the Yale University School of Medicine and his colleagues, and by Andrew Prayle, of Queens Medical Center in the UK, and his co-authors, a hefty chunk of trial findings is still awaiting release—long past publication deadlines....“When the word ‘mandatory’ turns out to mandate so little, the need for stronger mechanisms of enforcement becomes very clear,” Lehman and Loder argued...."