1. Research Unit for General Practice, Bartholins Allé 2, 8000 Aarhus C, Denmark
2. Department of Public Health, Aarhus University, Bartholins Allé 2, 8000 Aarhus C, Denmark
3. Faculty of Sport and Health Sciences, Research Centre for Health Promotion, University of Jyväskylä, Keskussairaalantie 4, 40014 Jyväskylä, Finland