Funding for this research was provided by:
National Natural Science Foundation of China (71473097)
Text and Data Mining valid from 2019-06-10
Received: 15 November 2018
Accepted: 31 May 2019
First Online: 10 June 2019
Ethics approval and consent to participate
: This study is based on published data, and therefore ethical approval is not a requirement. The original CHARLS was approved by the Ethical Review Committee (IRB) at Peking University in June 2008 (IRB00001052–11015). A “Letter to the Residents” leaflet was sent to the selected households. All residents participated provided written consent to the arrangements for the survey.
: Not applicable.
: The authors declare that they have no competing interests.