[1] Univ Warwick, Warwick Med Sch, Warwick Clin Trials Unit, Coventry, W Midlands, England
[2] Univ Cambridge, THIS Healthcare Improvement Studies Inst, Cambridge, England
[3] Cambridge Univ Hosp, Cambridge, England
[4] Univ Cambridge, Sch Clin Med, Addenbrookes Hosp, Hills Rd, Cambridge, England
[5] Univ Leeds, Natl Inst Hlth Res, Clin Res Network, Canc Cluster, Leeds, W Yorkshire, England
[6] Univ Southampton, Sch Hlth Sci, Southampton, Hants, England
[7] Univ Hosp Southampton NHS Fdn Trust, Southampton, Hants, England
[8] Resuscitat Council UK, 5th Floor,Tavistock House North,Tavistock Sq, London WC1H 9HR, England
[9] Marie Curie Hosp, Edinburgh EH10 7DR, Midlothian, Scotland
[10] NHS Fdn Trust, Univ Hosp Birmingham, Birmingham, W Midlands, England