Text and Data Mining valid from 2019-11-23
Received: 29 July 2019
Accepted: 12 November 2019
First Online: 23 November 2019
Compliance with ethical standards
: This study was approved by the local institutional ethical review board (Comitato Etico Milano Area 2, Fondazione IRCCS Ca’Granda Ospedale Maggiore Policlinico).
: The authors declare that they have no conflict of interest.