[1] Univ Ostrava, Fac Med, Dept Epidemiol & Publ Hlth, Ostrava, Czech Republic
[2] Univ Ostrava, Fac Med, Dept Nursing & Midwifery, Ostrava, Czech Republic
[3] Univ Ostrava, Univ Hosp Ostrava, Dept Surg, Ostrava, Czech Republic
[4] Univ Ostrava, Fac Med, Ostrava, Czech Republic
[5] Comenius Univ, Inst Hyg, Fac Med, Bratislava, Slovakia