Funding for this research was provided by:
Ministry of Health, Labour and Welfare (H28-junkankitou-ippan-009 and H30-choju-ippan-007, 19AA2007)
Received: 23 October 2019
Accepted: 12 April 2020
First Online: 26 April 2020
Ethics approval and consent to participate
: All participants’ identifiers were removed from the dataset. The present study was approved by the ethics committee of the University of Tsukuba (#1166). Because of the anonymous nature of the data, informed consent from individual participants was waived. Administrative permissions by Tsukuba city, Ibaraki, Japan were acquired by our team to access the data used in our research.
: Not applicable.
: Nanako Tamiya is Editorial Board Member.