[1] Univ Manchester, Sch Psychol Sci, Manchester M13 9PL, Lancs, England
[2] Univ Manchester, Personal Social Serv Res Unit, Manchester M13 9PL, Lancs, England
[3] Univ Turku, Dept Nursing Sci, Turku, Finland
[4] Lund Univ, Dept Hlth Sci, Lund, Sweden
[5] Univ Witten Herdecke, Sch Nursing Sci, Fac Hlth, Witten, Germany
[6] Univ Hosp Toulouse, INSERM 1027, Dept Geriatr Med, Toulouse, France
[7] Maastricht Univ, Dept Hlth Serv Res, Maastricht, Netherlands
[8] Hosp Clin Barcelona, Barcelona, Spain