Text and Data Mining valid from 2018-03-15
Received: 6 March 2017
Accepted: 1 March 2018
First Online: 15 March 2018
Ethics approval and consent to participate
: This study used retrospective and anonymized administrative data of patients who gave their consent to the use. Therefore this type of study was exempted from approval by an ethics committee.
: Not applicable.
: The authors declare that they have no competing interests.
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