1. Department of Public Health and Paediatric Sciences, University of Turin, Turin, Italy
2. Department of Public Health and Paediatric Sciences, University of Turin, Via Santena, 5 bis, Turin 10126, Italy
3. Department of Control and Computer Engineering, Politecnico di Torino, Torino, Italy
4. Epidemiology Unit, Local Health Unit TO3, Grugliasco, Italy