Ehrenstein V, Hernandez RK, Ulrichsen SP, et al. Rosiglitazone use and post-discontinuation glycaemic control in two European countries, 2000–2010. BMJ Open 2013;3:e003424. In the section ‘Ethics approval’ the record number with the Danish Data Protection Agency is incorrect. The sentence should read: ‘Ethics approval This study was approved by the Danish Data Protection Agency (record number 2004-41-4693) and by the Independent Scientific Advisory Committee of the GPRD.’