[1] Great Ormond St Hosp Sick Children, Inst Child Hlth, London WC1N 3JH, England
[2] Kings Coll London, Ctr Nursing & Allied Hlth Profess Res, London WC1N 3JH, England
[3] John Radcliffe Hosp NHS Trust, Oxford OX3 9DU, England
[4] Univ Southampton, Sch Nursing & Midwifery, Southampton SO17 1BJ, Hants, England
[5] Kings Coll London, Florence Nightingale Sch Nursing & Midwifery, London SE1 8WA, England