6. Acknowledgments
This work was supported by the Natural Science Foundation of Fujian Province (2017J01378).
7.Data Availability StatementSome or all data, models, or code generated or used during the study are available from the corresponding author by request.
8.Compliance with ethical standards
Consent The study was approved by the Institutional Ethics Committee of Zhongshan Hospital, Medical College Xiamen University, and conforms to the ethical guidelines of the Declaration of Helsinki. Requirement for individual patient consent forms was waived due to the retrospective, observational nature of the study.
9.Disclosures The authors report no conflicts of interest.