Systematic investigation of childhood sleep-disordered breathing (SDB) in Beijing: validation of survey methodology

OBJECTIVE: To systematically investigate and validate the survey methodology for the epidemiological study of childhood sleep-disordered breathing (SDB) in mainland China using the Mandarin version of the Pediatric Sleep Questionnaire-Sleep-Related Breathing Disorder (PSQ-SRBD). DESIGN: A cross-sectional study using randomised, stratified, multistage, cluster sampling method. SETTING: A total of 11 kindergartens, 7 primary schools and 8 middle schools from 7 districts of Beijing, China. PARTICIPANTS: A total of 9198 children with valid questionnaires (4736 boys and 4462 girls; age range 3.0–14.4 years) were included. PRIMARY AND SECONDARY OUTCOME MEASURES: Data on sociodemographic characteristics and PSQ-SRBD were collected. The score on PSQ-SRBD and the included factors were calculated with the effective data after data cleaning. Logistic regression and factor analysis with the principal components method were used to evaluate the validity of the questionnaire; reliability was assessed by retesting 5% of the respondents after 2±4 weeks of the initial test, and the intraclass correlation coefficient was calculated. RESULTS: The effective response rate of80.54% matched the sociodemographic characteristics of the respondents with respect to age group ratio and sex ratio in Beijing. With regard to construct validity of the PSQ-SRBD, the item score, except that of ‘delayed growth’, was highly correlated to the SRBD score as assessed by the logistic regression model. The exploratory factor analysis displayed a credible construct validity, with majority of the items grouped as the original dimensions. The test–retest reliability coefficient of each dimension’s score ranged from 0.758 to 0.901, with an SRBD score of 0.730 indicating significant retest reliability. CONCLUSIONS: This study conducted and validated a successful survey methodology for investigation of childhood SDB in Beijing, China. The questionnaire demonstrated credible construct validity and retest reliability, thereby supporting the applicability and generalisability of the PSQ-SRBD in a large epidemiological survey of childhood SDB in China.