[1] Great Ormond St Hosp Sick Children, London WC1N 3JH, England
[2] Univ Cent Lancashire, Dept Nursing, Children Families & Life Transit Res Grp, Preston PR1 2HE, Lancs, England
[3] Royal Hosp Sick Children, Glasgow G3 8SJ, Lanark, Scotland
[4] Royal Coll Anaesthetists, Patient Liaison Grp, London WC1R 4SG, England
[5] Royal Hosp Sick Children, Edinburgh EH9 1LF, Midlothian, Scotland
[6] Royal United Hosp, Bath BA1 3NG, Avon, England
[7] UCL Inst Child Hlth, London WC1N 1EH, England