This study determined distinct latent classes of mobile phone usage and examined the association of each class with sleep problems among 4,869 children aged 7–17 years in the Hokkaido Birth Cohort Study (January 2020 to July 2021). Parent–child dyads reported mobile phone usage and sleep problems were evaluated using the brief version of the Japanese Children’s Sleep Habits Questionnaire. Five mobile phone use classes were identified: lowest use, low use, high on mobile phone calls and SMS, high on internet activities, and overall high use. The lowest use class was more common in elementary school students, while higher use classes predominated in older students. Multiple logistic regression analysis showed that low use (odds ratio OR=1.07, 95% confidence interval CI: 1.02–1.14), high on mobile phone calls and SMS (OR=1.42, 95% CI: 1.32–1.53), and overall high use (OR=1.28, 95% CI: 1.20–1.36) were associated with sleep problems. In stratified analysis of elementary school students, low use (OR=1.14, 95% CI:1.06–1.23), high on mobile phone calls and SMS (OR=1.53, 95% CI: 1.41–1.67), and overall high use (OR=1.26, 95% CI: 1.12–1.41) were associated with sleep problems. Conversely, among junior high and high school students, only overall high use (OR=1.22, 95% CI: 1.12–1.33) was associated with sleep problems. The findings show that elementary school students were more susceptible to sleep problems, which may be attributable to behavioral disruptions and physiological effects. However causal inference cannot be drawn due to cross-sectional nature of the study, • Latent class analysis identified five distinct patterns of mobile phone use • Sleep problems linked to low use, high mobile phone calls, SMS and overall high use • Junior high school and higher, only overall high use was linked to sleep problems • No association between high use for internet activities and sleep problems • Mobile phone’s influence of behavioral factors rather than RF-EMF exposure
Ajmal et al. (Wed,) studied this question.