[1] Univ Stirling, Nursing Midwifery & Allied Hlth Profess Unit, Stirling FK9 4LA, Scotland
[2] Univ York & Hull, Dept Hlth Sci, York, N Yorkshire, England
[3] UCL, Dept Psychol, London, England
[4] Univ Manchester, Sch Med, Dept Behav Med, Manchester, Lancs, England
[5] Community Forens, Forth Valley NHS, Stirling, Scotland