[1] UCL, Mental Hlth Sci Unit, London, England
[2] Univ Manchester, Dept Old Age Psychiat, Manchester, Lancs, England
[3] Swansea Univ, Sch Med, Swansea, W Glam, Wales
[4] Bangor Univ, Dementia Serv Dev Ctr Wales, Bangor, Gwynedd, Wales
[5] Univ Bangor, N Wales Org Randomised Trials Hlth & Social Care, Bangor, Gwynedd, Wales
[6] Univ Hull, Inst Rehabil, Kingston Upon Hull HU6 7RX, N Humberside, England
[7] London Sch Econ & Polit Sci, London, England
[8] Kings Coll London, Inst Psychiat, London WC2R 2LS, England
[9] UCL, Dept Clin Psychol, London, England