Funding for this research was provided by:
Young Scholars Program of Shandong University (2017WLJH42)
Received: 24 June 2019
Accepted: 12 February 2020
First Online: 19 February 2020
Ethics approval and consent to participate
: The study was approved by the Ethics Committee of the School of Nursing at Shandong University (2017-R-102), and all participants in the study voluntarily joined through informed consent.
: Not applicable.
: The authors declare that they have no competing interests.