Funding for this research was provided by:
Yamaji Fumiko Nursing Research Fund
Japan Academy of Midwifery’s Research Fund
Japan Society for the Promotion of Science (26670993)
Received: 16 October 2020
Accepted: 2 January 2021
First Online: 19 January 2021
Ethics approval and consent to participate
: All study participants provided informed consent, and the study design was approved by the Institutional Review Board of St. Luke’s International University, Tokyo, Japan (Approval no. 15–064). The date of approval was November 20, 2015.
: Not applicable.
: The authors declare that they have no competing interests.