Text and Data Mining valid from 2019-02-11
Received: 23 February 2018
Accepted: 7 February 2019
First Online: 11 February 2019
Ethics approval and consent to participate
: Due to the retrospective study design involving electronic health records and no additional interventions, written informed consent was not obtained from the participants, which was approved by the Ethics Committee of Sichuan University West China Hospital (No. 315, 2016).
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