Received: 18 November 2020
Accepted: 22 March 2021
First Online: 1 April 2021
: This study was approved by the Kawasaki Medical School Ethics Committee (Approval No. 2632–4). Formal consent is not required for this type of study. However, we informed the participants who went for an annual health check-up during the target period about the research study and provided them with an opportunity to opt out. We deleted their personal data if they did not wish to participate in the research.
: Not applicable.
: The authors declare that they have no competing interests.