Received: 8 April 2020
Accepted: 28 July 2020
First Online: 7 August 2020
Ethics approval and consent to participate
: The study was performed in accordance with the guidelines of the Declaration of Helsinki. The study was approved by the Ethics Committee of the University of Pavia on October 6, 2009 (Committee report 3/2009). All the participants provided written informed consent.
: Not applicable.
: The authors declare that they have no competing interests.