Received: 22 February 2021
Accepted: 7 June 2021
First Online: 12 June 2021
: This study was approved by the Ethics Commission of Shandong Provincial Chest Hospital (Shandong Provincial Public Health Clinical Center), Shandong University, (2020XKYYEC-03).
: All authors agree with the content of the manuscript.
: The authors declare that they have no competing interests.