Małgorzata Gajewska1, Katarzyna Lewtak1, Jacques Scheres2,3, Piotr Albrecht4, Paweł Goryński5. 1. Department of Health Promotion and Postgraduate Education, National Institute of Public Health - National Institute of Hygiene, Warsaw, Poland. 2. Maastricht University Medical Centre, Maastricht, The Netherlands. 3. Department of Organization, Health Economics and Hospital Management, National Institute of Public Health - National Institute of Hygiene, Warsaw, Poland. 4. Department of Paediatric Gastroenterology and Nutrition, Medical University of Warsaw, Poland. 5. Centre for Monitoring and Analyses of Population Health Status and Health Care System, National Institute of Public Health - National Institute of Hygiene, Warsaw, Poland.