[1] Univ Highlands & Isl, Inst Hlth Res & Innovat, Inverness, Scotland
[2] NHS Highland, Dept Clin Psychol, New Craigs Psychiat Hosp, Inverness, Scotland
[3] NHS Highland, Nairn Healthcare Grp, Inverness, Scotland
[4] Harvard Univ, Inst Quantitat Social Sci, Cambridge, MA 02138 USA
[5] Univ Glasgow, Inst Hlth & Wellbeing, Glasgow, Lanark, Scotland
[6] NHS Highland, Cardiac Unit, Raigmore Hosp, Inverness, Scotland
[7] NHS Highland, Dept Psychiat, New Craigs Psycniatrlc Hosp, Inverness, Scotland
[8] UCL, Med Sch, Royal Free Hosp, London, England
[9] Scottish Rural Coll, Epidemiol Res Unit, Edinburgh, Midlothian, Scotland