Commercial interests are influencing medical review articles, NPR reports. Such articles are important, it adds, as they synthesize findings from a range of papers.
But Stanford University's John Ioannidis tells NPR that too many such meta-analyses are now being published and that researchers who have financial skin in the game are writing many of them. In a recent paper published in the Milbank Quarterly, Ioannidis examined reviews and meta-analyses published between 1986 and 2015 and found that the number of systematic reviews published each year between 1991 and 2014 increased by 2,728 percent and the number of meta-analyses increased by 2,635 percent. By contrast, he notes that the number of all PubMed-indexed items increased by 153 percent.
In particular, Ioannidis focused on papers discussing anti-depressants. He reports that 185 meta-analyses about such drugs were published between 2007 and 2014, and he tells NPR that this means there are some 25 review articles each year about the same drugs for the same indication.
He further estimates that some 80 percent of those articles were funded by drug manufacturers or had other conflicts of interest. "They can get the results or at least the interpretation that fits their needs," Ioannidis tells NPR. "So you have the most powerful and most prestigious design in current medical evidence, and it can be easily manipulated as an advertisement, as a marketing tool."