Authors: O Noel Gill; Yvonne Spencer; Angela Richard-Loendt; Carole Kelly; Reza Dabaghian; Lynnette Boyes; Jacqueline Linehan; Marion Simmons; Paul Webb; Peter Bellerby; Nick Andrews; David A Hilton; James W Ironside; Jon Beck; Mark Poulter; Simon Mead; Sebastian Brandner Journal: BMJ Date: 2013-10-15