1 Department of Hygiene and Human Ecology, Faculty of Medical Sciences, University of Kragujevac and Institute of Public Health Kragujevac Kragujevac, Serbia.
2 Center for Informatics and Biostatistics, Institute of Public Health Kragujevac Kragujevac, Serbia.
3 Department of Social Medicine, Faculty of Medical Sciences, University of Kragujevac, Kragujevac and Institute of Public Health Kragujevac Kragujevac, Serbia.