1. Department of Hematology and Oncology, Institute of Clinical Medicine, University of Tartu, Tartu, Estonia;
2. Department of Epidemiology and Biostatistics, National Institute for Health Development, Tallinn, Estonia;
3. Institute of Family Medicine and Public Health, University of Tartu, Tartu, Estonia;
4. Department of Radiotherapy and Oncological Therapy, Haematology and Oncology Clinic, Tartu University Hospital, Tartu, Estonia