Funding for this research was provided by:
Shantou Science and Technology Project (190626165269955)
Received: 29 September 2019
Accepted: 29 July 2020
First Online: 12 August 2020
Ethics approval and consent to participate
: The study was approved by the Ethics Committee of both the Sixth Affiliated Hospital of Sun Yat-sen University and the Second Affiliated Hospital of Shantou University Medical College and adhered to the tenets of the Declaration of Helsinki. Because the study is a retrospective study, it is impossible to recall each patient one by one and sign the inform consents form in person. Therefore, the inform consents were obtained by telephone (verbal), and the ethical committee approved this procedure.
: Not applicable.
: The authors declare that they have no competing interests.