1. Centre for Health Services and Nursing Research, Katholieke Universiteit Leuven, Kapucijnenvoer 35/4, B-3000 Leuven, Belgium
2. University Hospitals of Leuven, Leuven, Belgium
3. Department of Heart Disease, Haukeland University Hospital, Bergen, Norway
4. Department of Public Health and Primary Health Care, University of Bergen, Bergen, Norway