[1] United Hosp Bristol & Weston NHS Fdn Trust, Bristol Royal Hosp Children, Bristol, England
[2] Univ Birmingham, Birmingham, England
[3] Royal United Hosp Bath NHS Fdn Trust, Bath, England
[4] Univ West England, Pain & Wellbeing, Bristol, England
[5] Natl Inst Hlth & Care Res NIHR, NIHR Nursing & Midwifery, Melbourn, England
[6] Hertfordshire Partnership Univ NHS Fdn Trust, St Albans, England
[7] Northumbria Univ, Dept Nursing Midwifery & Hlth, Newcastle upon Tyne, England
[8] Newcastle upon Tyne Hosp NHS Fdn Trust, Newcastle upon Tyne, England
[9] Oxford Brookes Univ, Oxford Inst Nursing Midwifery & Allied Hlth Res, Nursing, Oxford, England
[10] Natl Inst Hlth & Care Res NIHR, Nursing & Midwifery, Melbourn, England
[11] Bristol Royal Hosp Children, Paediat Intens Care Unit, Womens & Childrens Directorate, Paul OGorman Bldg,Upper Maudlin St, Bristol BS2 8BJ, England