1. Institute of Occupational, Social and Environmental Medicine; Heidelberg University; Mannheim Germany
2. Mannheim Institute of Public Health; Social and Preventive Medicine; Heidelberg University; Mannheim Germany
3. Institute for Health Services Research and Health Economics; University of D€usseldorf; D€usseldorf Germany
4. Institute for Health Services Research and Health Economics; German Diabetes Centre; Düsseldorf Germany
5. German Centre for Diabetes Research; München-Neuherberg; Germany
6. Department of Clinical Psychology; University of Amsterdam; Amsterdam The Netherlands