Received: 13 January 2021
Accepted: 7 May 2021
First Online: 20 May 2021
: This study was approved by the Ethics Committee of the Tianjin Medical University General Hospital (Tianjin, China).
: We were exempted from obtaining informed consent because this was a secondary analysis of previously published studies.
: Written informed consent for publication was obtained from all participants.
: The authors declare that they have no competing interests.