Study objectives: To estimate the prevalence of snoring, witnessed sleep apnea, teeth grinding, primary and secondary nocturnal enuresis, and sleep duration in Hong Kong primary school children.
Design: Cross-sectional telephone questionnaire survey in a community.
Participants: A total of 3,047 6- to 12-year-old apparently healthy children.
Intervention: Those who agreed to the study were contacted by telephone. Survey questions were asked about the symptoms of the different sleep disorders, and the frequency of each positive symptom was noted for the preceding 1 week.
Outcome measures: Prevalence and risk factors of sleep disorders in Hong Kong primary school children.
Results: The prevalence of the following sleep symptoms was listed as follows: habitual snoring (10.9%), witnessed sleep apnea (1.5%), nocturnal enuresis (5.1%), and sleep teeth grinding (20.5%). Significant risk factors for habitual snoring included witnessed sleep apnea, mouth breathing during sleep, snoring in first-degree relatives, headache on rising, male gender, allergic rhinitis, and sleep teeth grinding. Significant risk factors for witnessed sleep apnea included habitual snoring, allergic rhinitis, tiredness on rising, and excessive daytime sleepiness. Poor academic results were associated with present of witnessed sleep apnea and absence of sleep teeth grinding. None of the sleep problem was associated with poor conduct results. The mean sleep duration was 8.79 h (SD 0.96).
Conclusions: This study provides epidemiologic data of sleep-disordered breathing, enuresis, sleep teeth grinding, and duration of sleep in Chinese primary school children in Hong Kong.