Funding for this research was provided by:
National Natural Science Foundations (81773540, 81573250, 81703315, 81573252)
Key R & D plan of Shaanxi Province (2019SF-143)
Text and Data Mining valid from 2020-03-18
Received: 18 September 2019
Accepted: 11 March 2020
First Online: 18 March 2020
Ethics approval and consent to participate
: The NHSS obtained ethics approval (license number: 2013 (65)) from the institutional review board of the Chinese National Bureau of Statistics. The NHSS is implemented by the MOH every 5 years and the MOH has pledged to protect the privacy of respondents and to facilitate the anonymous analysis of the data according to article 14 of the third chapter of the Statistics Law of the People’s Republic of China. For these reasons, a written consent was not required. The investigators read the informed consent statement on the second page of the questionnaire and verbally asked for the interviewees’ permission. Once the interviewees or their caregivers or guardians (in the case of children) had verbally consented to participate in this study, the investigators would sign their own names at the beginning of the questionnaire.
: Not applicable.
: The authors declare that they have no competing interests.