Text and Data Mining valid from 2019-06-19
Received: 11 March 2019
Accepted: 28 May 2019
First Online: 19 June 2019
Ethics approval and consent to participate
: The study was approved by the Ethics Committee of Chinese Center for Disease Control and Prevention (No. 201625) and Ethics Advisory Group of The Union, Paris, France (EAG number 22/18). The written informed consent process and the provision USD 15 to patients (as a reimbursement for costs related to travel to BMU office for the interview) was approved by the ethics committee.
: Not applicable.
: The authors declare that they have no competing interests.