Funding for this research was provided by:
China Medical Board (16-259)
Received: 7 October 2019
Accepted: 20 November 2019
First Online: 29 November 2019
Ethics approval and consent to participate
: This study was approved by Peking University Institutional Review Board (IRB number: IRB00001052–18005). No patients were involved in developing outcome measures and no analyses included any identifiable patient data.
: Not required.
: None declared.