Funding for this research was provided by:
National Natural Science Foundation of China (81600927)
Beijing Municipal Administration of Hospitals Clinical Medicine Development of Special Funding Support (ZYLX201706)
Ministry of Health Welfare Industry Special Fund (201002011)
Beijing Municipal Health Bureau Research Fund (Jing 17-12)
Milstein Medical Asian American Partnership Foundation Project Award in Geriatrics (2018)
Text and Data Mining valid from 2019-02-27
Received: 22 May 2018
Accepted: 4 February 2019
First Online: 27 February 2019
Ethics approval and consent to participate
: This study was approved by the ethics review board of Xuanwu Hospital, Capital Medical University and all the participants provided written informed consent.
: Not applicable.
: The authors declare that they have no competing interests.
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