Funding for this research was provided by:
National Institutes of Health
Received: 23 December 2019
Accepted: 23 April 2020
First Online: 13 May 2020
Ethics approval and consent to participate
: The participants subsequently provided their written consent to participate by returning the questionnaire. The present study was approved by the Ethics Committee of the Fukushima Medical University (#1316) and Nippon Medical School (approval code, 29–18).
: Not applicable.
: The authors declare that there are no competing interests.