[1] Guys & St Thomas NHS Fdn Trust, Occupat Hlth Serv, London SE1 7NJ, England
[2] Kings Coll London, Sch Life Sci & Med, London SE1 7UL, England
[3] Univ Southampton, Versus Arthrit Ctr Musculoskeletal Hlth & Work, UK Med Res Council, Southampton SO16 6YD, Hants, England
[4] Univ Aberdeen, Epidemiol Grp, Sch Med Med Sci & Nutr, Aberdeen AB25 2ZD, Scotland
[5] Bath Spa Univ, Psychol Dept, Bath BA2 9BN, Avon, England
[6] Nottingham Trent Univ, Dept Psychol, Nottingham NG1 4FQ, England
[7] Univ Glasgow, MRC CSO Social & Publ Hlth Sci Unit, Glasgow G3 7HR, Lanark, Scotland