Funding for this research was provided by:
Tianjin Municipal Bureau of Public Health (13KG119)
Received: 24 March 2020
Accepted: 28 May 2020
First Online: 22 June 2020
Ethics approval and consent to participate
: The study was conducted in accordance with the regulations and ethics followed at Tianjin Mental Health Center and in compliance with the Declaration of Helsinki. The study protocol was approved by the medical ethics committee of the Tianjin Mental Health Center and all respondents signed informed consent before participation.
: Not applicable.
: The authors declare that they have no competing interests.