[1] Univ Manchester, Manchester Acad Hlth Sci Ctr, Sch Hlth Sci, Div Nursing Social Work & Midwifery, Manchester, Lancs, England
[2] Univ Exeter, Med Sch, St Lukes Campus, Exeter, Devon, England
[3] Keele Univ, Res Inst, Primary Care & Hlth Sci, West Midlands CLAHRC, Newcastle, England
[4] Manchester Acad Hlth Sci Ctr, Greater Manchesters Acad Hlth Sci Network, Hlth Innovat Manchester, Manchester, Lancs, England
[5] Univ Manchester, Ctr Biostat, Inst Populat Hlth, Manchester, Lancs, England
[6] Univ York, Dept Hlth Sci, York, N Yorkshire, England
[7] Univ Leeds, Fac Med & Hlth, Leeds Inst Hlth Sci, Leeds, W Yorkshire, England