Fujiwara, Aya http://orcid.org/0000-0001-9928-1946
Okada, Emiko
Okada, Chika
Matsumoto, Mai
Takimoto, Hidemi
Article History
Received: 23 July 2019
Accepted: 26 February 2020
First Online: 11 March 2020
Compliance with ethical standards
:
: All authors declare that there was no conflict of interest.
: This study was conducted according to the guidelines laid down in the Declaration of Helsinki, and verbal informed consent was obtained from all individual participants. Under Article 33 of the Statistics Act, the Ministry of Health, Labour and Welfare anonymised individual level NHNS data, and provided the first author with datasets for this study. This analysis was exempted from the need for ethical review and institutional review board approval because, according to the Ethical Guidelines of Epidemiological Research established by the Ministry of Education, Culture, Sports, Science and Technology and the Ministry of Health, Labour and Welfare [CitationRef removed], only anonymized data were used.