Japanese Sleep Questionnaire for Elementary Schoolers (JSQ-ES): validation and population-based score distribution.

OBJECTIVE

The Japanese Sleep Questionnaire for Elementary Schoolers (JSQ-ES) was developed to measure the sleep habits and disturbances of Japanese children. The current study aimed to present psychometric properties and describe the score distribution of the JSQ-ES. In addition, it examined correlations between the sleep and daytime behavior of school-aged children.

METHOD: Guardians of 4369 elementary school children and 100 children diagnosed with sleep disorders in two clinics completed the JSQ-ES.

RESULTS

Exploratory factor analysis and confirmatory factor analysis suggested a nine-factor structure. The JSQ-ES internal consistency was 0.876 and 0.907 for the community and clinical groups, respectively. Score distribution differences were observed between the two groups. A cut-off point of 80 was identified for the total JSQ-ES score.

CONCLUSIONS

Exploratory factor analysis and confirmatory factor analysis suggested a nine-factor structure: (1) restless legs syndrome; (2) sleep-disordered breathing; (3) morning symptoms; (4) nighttime awakenings; (5) insomnia; (6) excessive daytime sleepiness; (7) daytime behavior; (8) sleep habits; and (9) irregular/delayed sleep phase. The study verified that the JSQ-ES is a valid and reliable instrument with which to evaluate Japanese sleep habits using a large population-based sample. The JSQ-ES may be useful in both clinical and academic settings.