Funding for this research was provided by:
National Natural Science Foundation of China (81700814)
Humanities Social Science Foundation of Ministry of Education (17YJCZH184)
Liaoning Education Science 13th Five-Year plan (JG17DB557)
Philosophy and Social Sciences promotion project of China Medical University (111-3110118083)
Received: 1 November 2018
Accepted: 24 June 2019
First Online: 3 July 2019
Ethics approval and consent to participate
: Ethics approval was obtained from the Ethics Committee of the First Affiliated Hospital of China Medical University (2015 [CitationRef removed]). The patient consent was waived, as utilization of anonymized history data does not require patient consent.
: Not applicable.
: The authors declare that they have no competing interests.