@article{oai:air.repo.nii.ac.jp:00006012,
 author = {Tsukada, Eriko and Kitamura, Shingo and Enomoto, Minori and Moriwaki, Aiko and Kamio, Yoko and Asada, Takashi and Arai, Tetsuaki and Mishima, Kazuo},
 issue = {10},
 journal = {PLOS ONE},
 month = {},
 note = {Objectives To investigate childhood obstructive sleep apnea syndrome (OSAS) and its role in daytime sleepiness among school-age children. Methods A questionnaire survey was conducted with 25,211 children aged 6-15 (mean, 10.39) years attending 148 elementary and 71 middle schools in 10 prefectures across Japan and their parents. Questions concerned 4 sleep habit items (bedtime, sleep onset latency, wake time after sleep onset, wake-up time) and 4 sleep disorder items (loud snoring, snorts/gasps, breathing pauses, seems very sleepy in the daytime). Total sleep time (TST) was calculated with sleep habits. Severe possible OSAS (p-OSAS) was defined as having loud snoring, snorts and gasps, or breathing pauses frequently (>= 5 times per week), and mild p-OSAS was rated as having any of these sometimes (2-4 times per week). Severe daytime sleepiness was defined as seeming very sleepy frequently and mild daytime sleepiness as seeming very sleepy sometimes. Results Mean prevalence of mild to severe p-OSAS and severe p-OSAS in children across all grade levels was 9.5% and 1.6%, respectively. p-OSAS was particularly prevalent in children at lower elementary levels, decreasing with advancing grade levels. Prevalence of mild and severe daytime sleepiness was 6.1% and 0.9%, respectively, among all children (7.0%). Prevalence of daytime sleepiness increased with advancing grade levels, particularly in middle-school level. Average TST was 8.4 +/- 2.2 h in both elementary and middle-school levels, and decreased as grades advanced, particularly in middle-school levels. Multivariate logistic regression analysis showed that middle-school level, TST < 8 h, and p-OSAS were independent factors for daytime sleepiness. Strong correlations were found between severe daytime sleepiness and severe p-OSAS or TST < 6 h, and between daytime sleepiness and loud snoring or breathing pauses. Conclusion p-OSAS may be an independent factor influencing daytime sleepiness in school-age children. Loud snoring and breathing pauses could be clinical markers for children with severe daytime sleepiness.},
 title = {Prevalence of childhood obstructive sleep apnea syndrome and its role in daytime sleepiness},
 volume = {13},
 year = {2018}
}