Study design and settings
This cross-sectional study was conducted in June 2019 as an online survey of 2,215 candidates, registered at a private online research firm, who raised preschool children; among them, 1,030 completed the questionnaire (response rate 46.5%). Participants were primary caregivers of children aged 2-6 years.
Prior to answering the questionnaire, the website administrator provided consent forms to respondents and informed them that completing the questionnaire was equivalent to their agreement to study participation. This study adhered to the Declaration of Helsinki, and was approved by the ethics committee of Nagoya City University Graduate School of Nursing (Approval No. 19014-2).