[1] Acad Resp Unit, Bristol, Avon, England
[2] Gloucestershire Royal Hosp, Gloucester, England
[3] Wythenshawe Hosp, Manchester, Lancs, England
[4] Royal Stoke Univ Hosp, Stoke, England
[5] East Cheshire NHS Trust, Macclesfield Gen Hosp, Macclesfield, Cheshire, England
[6] Guys & St Thomas Hosp, London, England
[7] Royal Gwent Hosp, Newport, Shrops, England
[8] Univ North Tees, Stockton On Tees, England
[9] NHS Ayrshire & Arran, Univ Hosp Ayr, Crosshouse, Ayr, Scotland
[10] James Cook Univ Hosp, Middlesbrough, Cleveland, England
[11] Addenbrookes Hosp, Cambridge, England
[12] UCL, MRC Clin Trials Unit, London, England
[13] UCL, Inst Global Hlth, London, England
[14] Churchill Hosp, Oxford, England