1. Department of Clinical Sciences and Community HealthUniversità Degli Studi di Milano Milan Italy
2. Unit of Cancer EpidemiologyCentro di Riferimento Oncologico Aviano IRCCS Aviano Italy
3. Department of OtorhinolaryngologySchool of Medicine and Surgery, University of Milano‐Bicocca Milan Italy
4. Department of Biomedical and Clinical SciencesUniversità Degli Studi di Milano, Sacco Hospital Milan Italy
5. Department of Methodology and StatisticsTilburg University Tilburg The Netherlands