1. Department of Internal Medicine and Hemodialysis, JZU Clinical Hospital "Dr Trifun Panovski," Bitola, Republic of Macedonia.
2. Department of Statistics, Faculty of Economics, University "St Kliment Ohridski", Prilep, Republic of Macedonia.
3. University Clinic of Nephrology, University "Ss. Cyril and Methodius", Medical Faculty, Skopje, Republic of Macedonia.