1. Department of Dermatovenereology; Military Medical Centre; Belgrade; Serbia
2. Faculty of Medicine; Institute of Epidemiology; University of Belgrade; Belgrade; Serbia
3. Faculty of Medicine; Institute of Medical Statistics and Informatics; University of Belgrade; Belgrade; Serbia
4. Faculty of Medicine; Institute of Social Medicine; University of Belgrade; Belgrade; Serbia
5. Clinic for Physical and Rehabilitation Medicine; Clinical Centre of Serbia; Belgrade; Serbia