[1] Univ Edinburgh, Sch Med, Sch Clin Sci & Community Hlth, Res Unit Hlth Behav & Change, Edinburgh EH8 9AG, Midlothian, Scotland
[2] Aston Univ, Birmingham B4 7ET, W Midlands, England
[3] Univ Wales, Social Inclus Res Unit, Wrexham LL11 2AW, Clwyd, Wales
[4] Lothian NHS Board, Edinburgh EH8 9RS, Midlothian, Scotland