RESEARCH TRIALS: May Exaggerate Drug Effectiveness
Drug research reports "tend to exaggerate the drugs' benefits, making them sound better than they really are," according to a new study in the Journal of the American Medical Association. The report notes that the skewed information could lead to patient harm, as doctors rely on research reports to make treatment decisions. Examining studies on drugs used to treat rheumatoid arthritis, postsurgical vomiting, depression, schizophrenia and immune deficiency resulting from cancer, researchers Helle Krogh Johansen and Peter Gotzsche found that "positive results tend to be published more often than negative ones, researchers sometimes publish the same study more than once and some poorly designed studies slip through the safety net of journal editors and expert reviewers who should screen them out." Dr. Drummond Rennie, JAMA deputy editor and author of the editorial accompanying the study, said, "Peer review does its best, but it's only as good as the people doing it." Another problem, "publication bias" in which positive studies are published faster and more often, causes medical literature to be "skewed." Dr. Kay Dickersin, an associate professor of community health at Brown University, noted that very few researchers submit studies with negative results. She said, "When we asked why, the major reason they gave is that the results just weren't interesting."
Another misleading phenomenon is publishing the same study more than once, in slightly altered format. And although publishing a study more than once makes "ambitious researchers look more productive," duplicative publishing might mislead doctors to think there are more positive studies of a drug than there really are. Indeed, the researchers estimate that current duplication practices lead to a 23% overestimate of the effectiveness of the drug in question (Grady, New York Times, 11/10).
In his editorial, Rennie argues, "For the manufacturer, increasing the number of reports on the same trials may confer a short-term commercial advantage: more reprints, by apparently different and unconnected authors, for company detail representatives to press into the hands of physicians, and a bigger dossier to file with the regulatory agencies. But over the long term, the manufacturers face a loss in credibility" (JAMA, 11/10).
Dr. Michael O'Connell, deputy director of the Mayo Clinic Cancer Center in Rochester, MN, said, "To publish the same data with entirely different authorship, as if it were an entirely different data set, is reprehensible. Readers would conclude there were two different studies that strengthened the conclusions." Dr. Bert Spilker, senior vice president for scientific and regulatory affairs at PhRMA, suggests that medical journals require authors to disclose where their studies previously had been published, and that institutional review boards evaluate them more closely (New York Times, 11/10).