1. Psychiatric Research Unit, Region Zealand, DK-4000 Roskilde, Denmark, Institute of Public Health, University of Southern Denmark, Winsløwvej 9, DK-5000 Odense C, Denmark,
2. Centre for Health Economics, University of York, York, UK
3. Institute of Public Health, University of Southern Denmark, Winsløwvej 9, DK-5000 Odense C, Denmark, DSI Institute for Health Services Research, Dampfærgevej 27-29 DK-2100 Copenhagen, Denmark, Australian Centre for Economic Research on Health, University of Queensland, Australia