1. Centre for Research on Health and Social Care Management (CERGAS), Bocconi University, Milan, Italy
2. Department of Statistical Science, University of Padua, Padova, Italy
3. SCaDU Epidemiology Unit, Regional Health Service ASL TO3, Grugliasco (TO), Italy
4. Deparment of Epidemiology, Lazio Regional Health Service, Italy
5. Department of Clinical and Biological Science, University of Turin, Italy