1. Unit for Health Promotion Research, University of Southern Denmark, Esbjerg, Denmark, , Institute for Biometrics and Clinical Epidemiology, Charité - University Medicine Berlin, Germany
2. Institute for Biometrics and Clinical Epidemiology, Charité - University Medicine Berlin, Germany
3. Unit for Health Promotion Research, University of Southern Denmark, Esbjerg, Denmark
4. Department of Statistics, IMADA, University of Southern Denmark, Odense, Denmark