Received: 19 January 2019
Accepted: 29 May 2019
First Online: 4 June 2019
Ethics approval and consent to participate
: This study was conducted with the approval of the University of Toyama ethics committee. Consent to participate in the study was provided in written format. For participants with cognitive impairment, consent was provided by their family members or proxies.
: Not applicable.
: The authors declare that they have no competing interests.