Vested interests

Controversy over the safety of a widely used drug is fertile ground for exploring conflicts of interest. Back in 1998 the controversy was over calcium channel antagonists. A paper in the New England Journal of Medicine reported that journal articles and letters were much more likely to support use of these drugs for treating cardiovascular disorders if their authors had financial ties to the drugs’ manufacturers (NEJM 1998;338:101-5). As Richard Smith, then editor of the BMJ, said at the time, the safety of calcium channel antagonists was a good subject to investigate “because it is intensely controversial and the market for the drugs is huge and lucrative” (BMJ 1998;317:291-2).

Perhaps for similar reasons Amy Wang and colleagues chose to look at the diabetes drug rosiglitazone (Avandia). Published in this week’s BMJ, their systematic review found just over 200 articles commenting on rosiglitazone and the risk of myocardial infarction (doi:10.1136/bmj.c1344). Articles that gave a favourable view on the risks were significantly more likely to have authors with financial ties to the manufacturers of antihyperglycaemic agents in general, and rosiglitazone in particular, than those with unfavourable views. The significant association persisted across a range of different methods of analysis.

One of the more important findings of the 1998 paper was that although two thirds of authors had financial links to the manufacturers, only two of the 70 articles disclosed them. In this week’s paper the rates of disclosure are better but still disappointing. Ninety of the 202 articles had authors with financial links to the manufacturers; 21 of these articles did not disclose the links, and three of the 21 said there were none. We’ve got to do better than this.

Rosiglitazone’s manufacturer, GlaxoSmithKline, strongly denies an increased risk of myocardial infarction, and the controversy has gained sufficient heat to reach the US congress. As Ray Moynihan reports (doi:10.1136/bmj.c1848), GSK stands accused of suppressing internal evidence of an increased risk, undermining the steering committee overseeing one of its trials, and other “strategies to minimise or misrepresent findings that Avandia may increase cardiovascular risk.” The Food and Drug Administration (FDA) hopes to resolve the matter at a further meeting of its advisory committee in July.

But drug regulators are prey to conflicts of interest of a different kind. The FDA and the European Medicines Agency have consistently argued to keep rosiglitazone on the market despite the safety concerns and despite the fact that there’s an alternative, pioglitazone, with a better safety profile. People are now suggesting that the decision on whether to remove a drug from the market should not be made by the same people who approved the drug in the first place. I agree. What we urgently need is independent post-marketing surveillance.

What we also need is reform of England’s libel laws. Simon Singh’s successful appeal allowing him to defend himself against the British Chiropractic Association’s libel action is good news (doi:10.1136/bmj.c1895), but it’s only the first step in what A C Grayling argues must be a complete overhaul (doi:10.1136/bmj.c1910). This time it’s the lawyers who have most to lose. The UK’s three main political parties will publish their manifestos in the next few weeks. Tell us what you’d like them to say on this and other issues.