[Follow-up study of school-age children's sleep quality in Shanghai]

China has undergone massive socioeconomic change during the past several years, and its impact on children's sleep is still unrecognized. Shanghai, as one of typical economically fast-developing cities, was chosen as observational city in this study, which was designed to explore trends in sleep quality in Shanghai school-aged children and related high risk factors on sleep quality.

Totally 884 fifth grade school-aged students were sampled by stratified cluster random sampling method from 10 primary schools of Shanghai in 2005, then four years later in 2009, 2161 same grade students were sampled from the same schools. Chinese version of Children's Sleep Habits Questionnaire (CSHQ) was used to evaluate 8 sleep quality parameters among those children, and high risk factors on school-aged children's sleep quality were investigated as well.

The prevalence of poor sleep quality decreased from 29.2% in 2005 to 27.9% in 2009, and among 8 sleep quality parameters, bedtime resistance decreased from 33.1% to 28.7%, sleep anxiety from 50.6% to 39.8%, night waking from 25.2% to 21.5%, and parasomnia from 51.2% to 45.8%. The factors, such as heavier homework burden, longer daily computer use, bright light during sleep, cosleeping, existence of chronic disease and irregular sleep habits of parents, were associated with poor sleep quality of school-aged children after adjusting for children's age, gender, and family social-economic status.

Part of sleep quality parameters improved during the past 4 years, but current situation is still tough with more than 1/4 poor sleep quality children. Helping children to develop good sleep hygiene as well as educating parents how to shape children's regular sleep habits might be effective methods to improve children's sleep quality.