Received: 1 August 2017
Accepted: 29 January 2018
First Online: 26 February 2018
Ethics approval and consent to participate
: The participation into the study was voluntary and participants could drop out at any time. Authors ensured confidentiality of information, and no financial incentive to participate in the study was offered. Since all data were de-identified and reported in aggregate, the study was deemed exempt from institutional review approval by the local Ethics Committee (Comitato Etico Interaziendale, Novara, Italy; study number Prot. 639/CE).
: Not applicable.
: The authors declare that they have no competing interests.
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