Unfavorable Clinical Trial Results Not Always ReportedJan 22, 2009 | Parker Waichman LLP Clinical trial reports tend to tout good news and neglect to report information that does not benefit industry. Those drug trials that offer positive results or which provide significant outcomes tend to receive publication in scientific journals, said ScienceDaily, while negative findings often go unreported, according to a review by international researchers from The Cochrane Collaboration, an organization that evaluates medical research.
"This publication bias has important implications for healthcare. Unless both positive and negative findings from clinical trials are made available, it is impossible to make a fair assessment of a drug's safety and efficacy," Sally Hopewell, study lead from the UK Cochrane Centre in Oxford, United Kingdom, reported ScienceDaily.
The international team of researchers analyzed “all the existing research in this area,” said ScienceDaily and found that not only were negative results published with less frequency, if negative results were actually published, publication would not occur for anywhere from one to four years, a significant disparity from positive results which tend to be published with greater expediency.
The review was comprised of five studies and results from one found that the blame is not with editors, but with investigators, with investigators explaining that they either did not have sufficient time or felt that findings were not of interest, to name a two, said ScienceDaily.
Kay Dickersin, another member of team, from Johns Hopkins University in Baltimore, Maryland, said, “The registration of all clinical trial protocols before they start should make it easier to identify where we are missing results," reported ScienceDaily. Dickersin added, said The Center for the Advancement of Health’s Behavior News Service, if positive results are published more often than negative, what we think we know isn’t really what we know. We might think a drug works, when it really doesn’t work, because the negative results haven’t been published.” Dickerson is also director of the U.S. Cochrane Center at John Hopkins’ Bloomberg School of Public Health.
Kirsty Loudan from Scotland and another member of the research team said, "Registration of trials and their results would help people conducting systematic reviews to look at both published and unpublished evidence, to reach reliable conclusions." The team believes the study points to an unanswered need for full clinical trial result disclosure. "The World Health Organisation recently found widespread support for the development of such a process," said Mike Clarke of Trinity College Dublin in Ireland, quoted Science Daily; Andy Oxman from the Norwegian Knowledge Centre for Health Services concluded, "Healthcare decisions need to be based on all the evidence, not just the most exciting results."
The Behavior News Service said that it’s the findings that hold a so-called “wow factor” that tend to find its way into prestigious scientific journals, describing the research as utilizing Cochrane’s systematic review, which reaches evidence-based conclusions after looking at both “content and quality of existing medical trials.” The review found that those results believed to be important, bearing “scientifically significant findings,” or possessing information on positive outcomes were nearly twice as likely—1.78 times—to be published, said The Behavior News Service. The studies concluded that about 73 percent of positive studies are published, while only about 41 percent of negative results appear in print.
The findings appear in the latest issue of The Cochrane Library, a publication of The Cochrane Collaboration.