[1] UCL, Global Business Sch Hlth, London, England
[2] Univ Cambridge, Dept Publ Hlth & Primary Care, Cambridge, England
[3] Nuffield Trust, 59 New Cavendish St, London W1G 7LP, England
[4] UCL, Dept Appl Hlth Res, Gower St, London WC1E 6BT, England
[5] Great Ormond St Inst Child Hlth, NIHR Children & Families Policy Res Unit, 30 Guilford St, London WC1N 1EH, England
[6] Univ Birmingham, Inst Appl Hlth Res, Coll Med & Dent Sci, 40 Edgbaston Pk Rd, Birmingham B15 2RT, England
[7] Univ Birmingham, Hlth Serv Management Ctr, Sch Social Policy, 40 Edgbaston Pk Rd, Birmingham B15 2RT, England