1. University of Oxford; Clinical Trial Service Unit; Richard Doll Building Rooseveld Drive Oxford UK OX3 7LF
2. COCHRANE COLLABORATION; CDCIG; 9 Homer Row London UK W1H 4AW
3. University of Oxford; Nuffield Department of Clinical Medicine; Cochrane Office Room 4401C John Radcliffe Hospital, 4th Floor Oxford UK OX3 9DU