1. National Institute of Public Health , Trubarjeva cesta 2 , Ljubljana , Slovenia
2. University of Ljubljana , Faculty of Medicine , Vrazov trg 2 , Ljubljana , Slovenia
3. University Clinic of Respiratory and Allergic Diseases Golnik , Golnik 36 , Golnik , Slovenia
4. University of Ljubljana , Faculty of Medicine, Chair of Internal Medicine , Zaloška cesta 7 , Ljubljana , Slovenia
5. University of Ljubljana , Chair of Public Health , Zaloška cesta 4 , Ljubljana , Slovenia
6. Department of International Health, School CAPHRI (Care and Public Health Research Institute) , Maastricht University , Maastricht , the Netherlands
7. Department of Public Health, Faculty of Medicine , University of Medicine , Tirana , Albania