Text and Data Mining valid from 2019-02-05
Received: 1 November 2018
Accepted: 21 January 2019
First Online: 5 February 2019
Compliance with ethical standards
: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported.
: All procedures followed were in accordance with the ethical standards of the responsible committee on human experimentation (institutional and national) and with the Helsinki Declaration of 1975, as revised in 2008.
: Each patient was assigned a unique identifier that was the same for all administrative databases. This identifier does not allow to disclose the patient’s identity and other sensitive data and therefore no informed consent was required from all patients for being included in the study.
: Giuseppe Seghieri.