Funding for this research was provided by:
National Health & Family Planning Commission, PR China
Received: 27 January 2018
Accepted: 10 August 2018
First Online: 24 August 2018
Ethics approval and consent to participate
: This study was approved by the Research Ethics Committee of the Chinese Academy of Medical Science & Peking Union Medical College. A statement explaining the informed consent to participate was included on the opening page of the survey. The participants were only able to complete the online questionnaire after accepting the terms of consent.
: Not applicable.
: The authors declare that they have no competing interests.
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