Researchers Find Link between Avandia Defenders and Drug Companies

Rochester, MNA team of researchers has found that many of the experts who defended Avandia against negative publicity actually have financial ties to drugmaker GlaxoSmithKline. The findings raise questions over the ethics of study authors who have ties to the pharmaceutical industry.


After a May 2007 study suggested that Avandia significantly increased the risk of heart attacks, a number of scientists released studies and commentaries in defense of the drug. A team of researchers at the Mayo Clinic went through more than 200 of these studies and found that 94 percent of authors who defended Avandia had ties to the pharmaceutical industry, compared with only 28 percent of those who expressed negative opinions.

Nearly half the authors had financial ties that amounted to a conflict of interest. What's more, approximately 25 percent of those with a financial conflict of interest did not disclose their financial ties to the pharmaceutical industry.

The study, published in the British Medical Journal on 3/18/10, concludes, "Disclosure rates for financial conflicts of interest were unexpectedly low, and there was a clear and strong link between the orientation of authors' expressed views on the rosiglitazone controversy and their financial conflicts of interest with pharmaceutical companies."

Researchers go on to note that the findings do not necessarily indicate a causal link between their stance on the risk of rosiglitazone. For example, it is not clear whether a financial tie to a drug company causes authors to write a positive opinion, or whether people with positive opinions of the drug are more likely to form relationships with the drug's manufacturers. However, the findings "underscore the need for further changes in disclosure procedures in order for the scientific record to be trusted."

Mary Anne Rhyne, a spokesperson for GlaxoSmithKline, defended Avandia: "Many of the articles reviewed were opinion pieces—editorials, commentaries or letters. It is important to note that the authors' conclusions do not impugn the validity of the scientific data."

The US Food and Drug Administration has said it is reviewing documents to examine whether Avandia increases the risk of heart attack and heart failure. A public hearing may be held in July.

The authors of the Mayo study called on journals to demand that their authors report their financial ties to the pharmaceutical industry. "Given the potential influence of financial conflicts of interest on the views expressed in articles, the low rate of disclosure by authors of editorials and commentaries is disappointing," they said.

The Mayo researchers reported that they had no financial ties to any entity that may pose a conflict of interest in their study.