1. Department of Cardiology, County Hospital Ryhov, Jönköping S-551 85, Sweden
2. Department of Primary Health Care, Göteborg University, Göteborg, Sweden
3. Department of Statistics, Örebro University, Örebro, Sweden
4. School of Social and Health Sciences, Halmstad University, Halmstad, Sweden
5. Department of Nursing, Lund University, Lund, Sweden