There are many types of scales used for children's OSAS screening worldwide. Spruyt and Gozal  found that a large number of children's sleep-related questionnaires and scales only reported about their reliability and validity within the study. Chervin et al  developed a children’s PSQ questionnaire based on American OSAS children’s sleep habits and risk factors. This questionnaire is the only recommended screening questionnaire in the 2012 OSAS guidelines of the American Academy of Pediatrics. Its sensitivity and specificity in the United States are as high as 85% and 81% respectively, which is the main reason why PSQ is superior to other children's sleep questionnaires in screening children's OSAS. However, due to differences in region, race, environment, living habits, and growth and development, it is necessary to evaluate its reliability, validity, and applicability before applying the questionnaireoutside the United States. Taiwan’s Wang et al  evaluated the reliability and validity of the Taiwan version of PSQ after surveying 173 Taiwanese children, and obtained conclusions applicable to OSAS screening of children and adolescents in Taiwan. Li Xiaodan and Tai Jun  studied the data of children in Beijing and evaluated the reliability, validity and screening ability of the simplified Chinese version of PSQ.
Sleep is of great significance to the growth and development of children, especially of the central nervous system . The secretion of growth hormone, which is necessary for children's physical development, appears mostly in the first slow-wave sleep after sleep initiation . Therefore, the quality of sleep may directly affect children's physical and mental development. Poor sleep qualitay may even cause behavioral problems . Therefore, good sleep quality plays a very important role in the development and maturity of children's central nervous system. At present, there are few studies on the use of maturity scales to investigate children's sleep disorders. Most studies simply use sleep questionnaires to measure sleep quality. The results obtained from such questionnaires often have poor reliability and validity.
This study used the PSQ scale recommended by the American Pediatric Association to investigate a large population of children and found that the average PSQ score of children in Beijing was 3.60 ± 2.69 points. About 8.87% of children scored above 7 points, suggesting that there may be a certain proportion of children in Beijing with sleeping problems.
The results of this analysis show that snoring may be an important factor in scoring high in PSQ, and the frequency of snoring has a clear positive relationship with PSQ score. As the frequency of snoring increases, the PSQ score is also higher. Previous articles reported that the proportion of snoring among school-aged children aged 6–14 in Beijing was about 9.08% . These resultsstrongly suggest that children with sleep disorders in Beijing cannot be ignored. In this study, it was found that younger children scored higher in the PSQ, with preschool children having the highest PSQ score, and adolescent children after the age of 12 having a lower PSQ score. In terms of sex, boys scored significantly higher than girls in PSQ. This suggests that more attention should be paid to the sleeping conditions of boys and preschool children.
The study also found that some activities before sleep such as eating, surfing the internet, and playing video games may be related to a higher PSQ score. Children who eat, surf the internet, and play video games before sleep all had relatively higher PSQ scores. Harvard University research shows that playing smartphones, watching TV shows, or playing video games before bedtime exposes individuals to blue light which can inhibit melatonin secretion and affect sleep quality and increasing disease incidence. Children and adolescents are in a period of growth and development in which the harms of poor sleep may begreater than in adults. After studying the influencing factors of children's sleep, professor Owens of the United States  found that playing games and watching TV for too long can seriously affectsleep quality in children.
The family is the main environment in children’s early life. Children's sleep will inevitably be affected by the family environment and parents' education methods. A quiet environment helps children to start and maintain sleep; parents who adopt persuasive education and who pay attention to parent-child communication often fostersgood emotional experience to their children, and thus effectively promoting good quality sleep. For parents who do otherwise, the lack of conducive enviroment to foster good sleeping habits in children makes it an easy environment for sleep disorders to develop. Poor sleep habits are an important factor influencing children's sleep disorders . Liu Xicheng et al  used the clinical questionnaire of the Sleep Center of Sydney Children's Hospital that sleep time generally decreased and the incidence of sleep disorders was higher among children in Beijing.
This research is innovative. First, this study uses the AAP approved PSQ questionnaire for the first time in China, thus the results are more reliable. Second, this study is based on a large-scale population survey and analysis which can more accurately reflect the sleep status of children in Beijing.Limitations includethe cross-sectional study design where relationships between factors and PSQ scoreswere analyzed at one point in time, and thus cannot confirmcausal relationships. Further studies are needed to confirm causality and association.