Received: 29 December 2017
Accepted: 19 June 2019
First Online: 26 July 2019
Ethics approval and consent to participate
: Participation by individuals capable of informed consent as subjects in this survey was voluntary and the informed consent was embedded in the cover letter of the email, an ethics approval from Nagasaki University not being required for an anonymous web-based survey. Written informed consent was obtained from participants by answering the first question of the survey (Q0. Have you read all the information about the study given in the cover letter and agreed to participate in this survey? - Yes/No).
: Not applicable
: The authors declare that they have no competing interests.