1. Unit of Biostatistics and Clinical Epidemiology, Department of Public Health, Experimental and Forensic Medicine, University of Pavia, 27100 Pavia, Italy
2. Unit of Occupational Medicine, Department of Public Health, Experimental and Forensic Medicine, University of Pavia, 27100 Pavia, Italy
3. Hospital Occupational Medicine Unit (UOOML), ICS Maugeri IRCCS, 27100 Pavia, Italy