Our electronic processes somehow mangled the order of authorship in the online full text version of this paper by Christian T Brown and colleagues (BMJ 2007;334:25-8, 6 Jan, doi: 10.1136/bmj.39010.551319.AE). Somehow the ninth author's name (Jan van der Meulen) had wrongly slipped into first place, ahead of Brown's. The correct order is therefore: Christian T Brown, Tet Yap, David A Cromwell, Lorna Rixon, Liz Steed, Kathleen Mulligan, Anthony Mundy, Stanton P Newman, Jan van der Meulen, Mark Emberton. The pdf and the print version did not contain the error, and the full (html) version has now been corrected.