1. Public Health Institute of Republic of Srpska, Regional Center Foča , Njegoševa 15, 73301 Foča , Republic of Srpska (Bosnia and Herzegovina)
2. Institute of Medical Statistics and Informatics, Dr Subotica 15, Faculty of Medicine, University of Belgrade , 11 000 Belgrade , Serbia
3. Institute of Epidemiology, Faculty of Medicine, University of Belgrade , Višegradska 26A, 11 000 Belgrade , Serbia