1. Institute of Social and Preventive Medicine (ISPM), University of Bern, Bern, Switzerland
2. Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece
3. Department of Primary Education, University of Ioannina, Ioannina, Greece
4. Bern Institute of Primary Care (BIHAM), University of Bern, Bern, Switzerland