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).
: (1) All authors have no relationships with companies that might have an interest in the submitted work over the previous 5 years; (2) their spouses, partners, or children have no financial relationships that may be relevant to the submitted work; and (3) none of the authors have nonfinancial interests that may be relevant to the submitted work.There are no ethical/legal conflicts involved in the article.
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