I didn’t want November to end without pointing Second Opinion readers to a terrific article published in this month’s issue of The Atlantic magazine. Reporter David H. Freedman profiles Greek physician and “meta-researcher” John Ioannidis, who for the last decade or so has been voraciously challenging the credibility of medical research.
After reading the article, you’ll have a much more skeptical — and thus healthier — attitude toward the much-publicized findings of medical-research studies.
[Ioannidis] and his team have shown, again and again, and in many different ways, that much of what biomedical researchers conclude in published studies — conclusions that doctors keep in mind when they prescribe antibiotics or blood-pressure medication, or when they advise us to consume more fiber or less meat, or when they recommend surgery for heart disease or back pain — is misleading, exaggerated, and often flat-out wrong. He charges that as much as 90 percent of the published medical information that doctors rely on is flawed. His work has been widely accepted by the medical community; it has been published in the field’s top journals, where it is heavily cited; and he is a big draw at conferences.
Given this exposure, and the fact that his work broadly targets everyone else’s work in medicine, as well as everything that physicians do and all the health advice we get, Ionnidis may be one of the most influential scientists alive. Yet for all his influence, he worries that the field of medical research is so pervasively flawed, and so riddled with conflicts of interest, that it might be chronically resistant to change — or even to publicly admitting that there’s a problem.
Even randomized trials, considered the most reliable type of study, end up being wrong up to 25 percent of the time, Ioannidis has found. Unfortunately, as Ioannidis reported in a 2005 paper, the medical community too often fails to notice research that disproves earlier findings (or vehemently rejects it — consider the anger unleashed last year by doctors as well as patients over revised mammography screening recommendations). Writes Freedman:
[Ioannidis] zoomed in on 49 of the most highly regarded research findings in medicine over the previous 13 years, as judged by the science community’s two standard measures: the papers had appeared in the journals most widely cited in research articles, and the 49 articles themselves were the most widely cited articles in these journals. These were articles that helped lead to the widespread popularity of treatments such as the use of hormone-replacement therapy for menopausal women, vitamin E to reduce the risk of heart disease, coronary stents to ward off heart attacks, and daily low-dose aspirin to control blood pressure and prevent heart attacks and strokes.
Ionnidis was putting his contentions to the test not against run-of-the-mill research, or even merely well-accepted research, but against the absolute tip of the research pyramid. Of the 49 articles, 45 claimed to have uncovered effective interventions. Thirty-four of these claims had been rested, and 14 of these, or 41 percent, had been convincingly shown to be wrong or significantly exaggerated. If between a third and a half of the most acclaimed research in medicine was proving untrustworthy the scope and the impact of the problem were undeniable.
One of the big, underlying problems of medical research is bias. “At every step in the process, there is room to distort results, a way to make a stronger claim or to select what is going to be concluded,” Ionnidis told Freedman. “There is an intellectual conflict of interest that pressures researchers to find whatever it is that is most likely to get them funded.” (And with much of that research now funded by drug companies, the pressure to get the “right” results is even greater.)
You can read Freedman’s entire article here.