Funding for this research was provided by:
Hunan Health Commission project (B2019002)
Chenzhou Science and technology Bureau (yfzx201908, zdyf201941 and zdyf201947)
Received: 31 March 2020
Accepted: 28 March 2021
First Online: 7 April 2021
: The study was approved by the ethics Committee of Chenzhou NO.1 People’s Hospital. No informed consent or other action on the part of the patients was required owing to anonymous analyses of the data.
: Not applicable.
: The authors declare that they have no competing interests.