Received: 21 April 2020
Accepted: 27 October 2020
First Online: 17 November 2020
Ethics approval and consent to participate
: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.This study complied with the Declaration of Helsinki and was approved by Ethics Committees of the Third Hospital of Hebei medical university. Except for illiterate patients,all patients provided written informed consent. Illiterate patients indicate their consent by“making their mark** on the consent form, which were consistent with the local law.
: Not Applicable.
: The authors declare that they have no conflict of interest.