1. Geriatric Unit, Department of Palliative Medicine, Poznań University of Medical Sciences, Poznań, Poland
2. Department of Geriatric Medicine and Gerontology, Poznań University of Medical Sciences, Poznań, Poland
3. Department of Immunobiology, Poznań University of Medical Sciences, Poznań, Poland
4. Department of Internal Medicine and Oncological Chemotherapy, Medical University of Silesia in Katowice, Katowice, Poland
5. Department of Nephrology, Transplantology and Internal Medicine, University of Medical Sciences, Poznań, Poland
6. Collegium Medicum, Faculty of Medicine, Cardinal Stefan Wyszyński University, Warsaw, Poland
7. School of Public Health, Centre of Postgraduate Medical Education of Warsaw, Warsaw, Poland