Funding for this research was provided by:
The key research and development (R&D) projects of Gansu Province (17YF1FA126)
Special fund project for doctoral training program of Lanzhou University Second Hospital (YJS-BD-25)
CuiYing Science and Technology Innovation plan project of Lanzhou University Second Hospital (CY2017-BJ05)
Received: 28 October 2020
Accepted: 26 January 2021
First Online: 20 February 2021
Ethics approval and consent to participate
: This retrospective chart review study involving human participants was in accordance with the ethical standards of the institutional and national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. This study received the Lanzhou University Second Hospital Ethical Committee approval (2017A-053).
: Not applicable
: All authors have no conflicts of interest or financial ties to disclose.