title: Validity of child sleep diary questionnaire among junior high school children.
abstract: BACKGROUND
  The validity of sleep quality and quantity indices as reported by schoolchildren has not been established. The purpose of this study is to evaluate the relationship between subjective sleep habits estimation and objective measurement data in schoolchildren.
  
  
  METHODS
  The study consisted of 42 healthy junior high school children aged 13-14. Sleep log information was gathered over 7 consecutive days, using a sleep-monitoring device (Actiwatch) and a questionnaire which covered the following aspects for sleep quality and quantity: bed time, sleep latency, sleep start, sleep end, wake up and assumed sleep length. The means of the sleep indices for 5 weekdays were used for analysis. Pearson's correlation coefficients and paired t-tests were used to evaluate the correlation and difference between subjective and objective sleep parameters.
  
  
  RESULTS
  The correlation coefficient between subjective and objective records was 0.49 (p < 0.001) for sleep latency, 0.99 (p < 0.001) for sleep start time, 0.99 (p < 0.001) for sleep end time, and 0.97 (p < 0.001) for assumed sleep length. The difference between subjective and objective records was 7.67 min (95% confidence interval [CI]: 4.64-10.71) for sleep latency, and 0:02 min (95% CI: -0:01-0:05) for sleep start time, 0:02 min (95% CI: 0:01-0:03) for sleep end time, and 8.19 min (95% CI: 4.93-11.45) for assumed sleep length.
  
  
  CONCLUSIONS
  Although children tended to overestimate sleeping hours, the correlation between subjective and objective sleep indices except sleep latency was quite high. Thus, children's sleep questionnaire can be applied to surveys for sleep habits screening.
authors.affiliation: Department of Welfare Promotion and Epidemiology, Faculty of Medicine, Toyama Medical and Pharmaceutical University, 2630 Sugitani, Toyama 930-0194, Japan.
authors.forename: Alexandru
authors.initials: A
authors.lastname: Gaina
authors.forename: Michikazu
authors.initials: M
authors.lastname: Sekine
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Chen
authors.forename: Shimako
authors.initials: S
authors.lastname: Hamanishi
authors.forename: Sadanobu
authors.initials: S
authors.lastname: Kagamimori
mesh_terms: D000293:Adolescent; D003625:Data Collection; D006801:Humans; D007564:Japan; D008297:Male; D012890:Sleep / Q000502:physiology*; D011795:Surveys and Questionnaires