Contribution to authorship
HBQ and NS contributed to the study design. YY, LC and JNX collected data. YY and QJD analyzed data and wrote this manuscript. XL and CT provided some advice on data analysis and helped editing this manuscript. HBQ and NS revised the manuscript and are corresponding authors of this study. All authors made substantial contributions to the paper and read and approved the final manuscript.
Details of ethics approval
 The study was approved by the ethics committee of the First Affiliated Hospital of Chongqing Medical University on 1 December 2019 (NO.20198101). An electronic informed consent was obtained before completing the questionnaire.