An advisory committee to the US Food and Drug Administration has recommended further restrictions on the drug rosiglitazone (Avandia), used to control type 2 diabetes. The decision came after two days of intense hearings on 13-14 July, outside Washington, DC.

There was no question about the effectiveness of the widely prescribed drug, but a trail of evidence indicated that long term use increased the risk of cardiovascular disease. The meeting focused on the quality of that evidence and the comparative merits of randomised controlled trials, observational studies, and a meta-analysis.

A consensus emerged that the data probably did indicate that rosiglitazone increased the risk of cardiovascular disease, possibly more so than did use of pioglitazone, a drug in the …