1. Department of Medical Statistics and Informatics, Faculty of Medicine The University of Niš Niš Serbia
2. The Institute of Public Health Niš Niš Serbia
3. School of Medicine, Institute for Rehabilitation University of Belgrade Belgrade Serbia
4. Department of Epidemiology, Faculty of Medicine The University of Niš Niš Serbia
5. Department of Social Medicine, Faculty of Medicine The University of Niš Niš Serbia
6. Pulmonary Diseases Clinic University Clinical Centre Niš Niš Serbia
7. Department of Pathophysiology, Faculty of Medicine The University of Niš Niš Serbia
8. Department of Microbiology and Immunology,Faculty of Medicine The University of Niš Niš Serbia