Received: 25 March 2019
Accepted: 19 August 2019
First Online: 30 August 2019
Ethics approval and consent to participate
: The study protocol was approved by the ethics committee at Nankai Medical Center (IRB approval number NH-H25-002) as an epidemiological study conducted on validated questionnaires and patient blood samples. Written consent for enrollment and publication was obtained from patients for the extended use of validated questionnaires and patient blood samples obtained for usual clinical practice. Patients were informed about the details of the study by a documented explanation form and were given the right to withdraw consent after enrollment.
: Not applicable.
: The authors declare that they have no competing interests.