Received: 24 April 2020
Accepted: 14 May 2020
First Online: 20 May 2020
Ethics approval and consent to participate
: The protocol of this retrospective observational study was approved by the local Ethics Committee (Comitato Etico Regionale delle Marche, number 2020-121). Written informed consent was not requested due to the retrospective study design.
: Not applicable.
: The authors declare that they have no competing interests.