Received: 8 May 2018
Accepted: 8 March 2019
First Online: 15 March 2019
Ethics approval and consent to participate
: Ethical approval was obtained from the Research Ethics Committee of the School of Medicine, Zhejiang University (ZGL201711–1). Both written consent and verbal consent were allowed according to the Ethics committee. Before the interview, participants were given a verbal explanation with the consent, and we recorded their consent.
: Not applicable.
: The authors declare that they have no competing interests.
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