Text and Data Mining valid from 2020-02-12
Received: 12 October 2019
Accepted: 30 January 2020
First Online: 12 February 2020
Ethics approval and consent to participate
: This study was approved by the ethics committee of Viet Duc University Hospital. All participants were informed of the study in detail and signed a consent form.
: Not applicable.
: The authors declare that they have no competing interests.