1. Chair of Epidemiology and Preventive Medicine, Department of Hygiene and Dietetics; Jagiellonian University Medical College; Krakow Poland
2. Department of Surgical Oncology; The Maria Sklodowska-Curie National Research Institute of Oncology, Krakow Branch; Department of Anatomy, Jagiellonian University Medical College; Krakow Poland
3. 2nd Department of General Surgery; Jagiellonian University Medical College; Krakow Poland
4. Centre for Evidence-Based Chinese Medicine; Beijing University of Chinese Medicine; Beijing China
5. Kleijnen Systematic Reviews Ltd; York UK