[1] Univ Belgrade, Inst Rheumatol, Sch Med, Belgrade 11000, Serbia
[2] Univ Belgrade, Inst Pathol, Sch Med, Belgrade 11000, Serbia
[3] Univ Belgrade, Inst Social Med & Informat, Sch Med, Belgrade 11000, Serbia
[4] Univ Belgrade, Inst Otorhinolaryngol, Sch Med, Belgrade 11000, Serbia