[1] Univ York, Dept Hlth Sci, York YO10 5DD, N Yorkshire, England
[2] Univ Adelaide, Sch Psychol, Adelaide, SA, Australia
[3] Fdn Brocher, Geneva, Switzerland
[4] Univ Lausanne, Inst Social & Prevent Med, Hlth Care Evaluat Unit, Lausanne, Switzerland
[5] Univ Bern, Dept Clin Res, Bern, Switzerland
[6] Univ Hosp Bern, Inselspital, Dept Neurol, CH-3010 Bern, Switzerland
[7] Clin Barmelweid, Dept Psychosomat Med, Barmelweid, Switzerland