Funding for this research was provided by:
Natural Science Foundation of Shandong Province (No.ZR2018MH025)
Primary Research & Developement Plan of Shandong Province (No.2019GSF108076)
Received: 23 May 2020
Accepted: 14 July 2020
First Online: 20 July 2020
Ethics approval and consent to participate
: These were waived as this study was only based on the summary results of previously published articles and individual patient data was not obtained or accessed.
: Not applicable.
: The authors declare that they have no competing interests.