Author contributions:
- Alessandra Sala: concept/design, data analysis and interpretation
- Roberto Lorusso: critical revision of article
- Marta Bargagna: data collection
- Stefania Ruggeri: statistical analysis
- Nicola Buzzatti: data collection
- Mara Scandroglio: supervision
- Fabrizio Monaco: supervision
- Eustachio Agricola: supervision
- Andrea Giacomini: supervision
- Roberta Meneghin: data collection
- Davide Schiavi: data collection
- Elisabetta Lapenna: supervision
- Paolo Denti: supervision
- Andrea Blasio: supervision
- Ottavio Alfieri: supervision
- Alessandro Castiglioni: supervision
- Michele De Bonis: concept/design, critical revision of article