title: Assessing insomnia in adolescents: comparison of Insomnia Severity Index, Athens Insomnia Scale and Sleep Quality Index.
abstract: OBJECTIVE
  To compare the psychometric properties of the Chinese versions of Insomnia Severity Index (ISI), Athens Insomnia Scale (AIS) and Sleep Quality Index (SQI) for assessment and screening of insomnia in adolescents.
  
  
  METHODS
  This is a school-based survey of 1516 adolescents aged 12-19 years. Sleep-wake habit questionnaire, ISI, AIS, SQI, Epworth Sleepiness Scale (ESS) and 12-item General Health Questionnaire (GHQ-12) were administered. Insomnia Interview Schedule was used to assess the severity of insomnia symptoms and DSM-IV-TR diagnosis of insomnia.
  
  
  RESULTS
  The Cronbach's alpha of ISI, AIS and SQI were 0.83, 0.81 and 0.65, respectively, and the 2-week test-retest reliability were 0.79, 0.80 and 0.72. All three scales had a 2-factor structure, and their scores were significantly correlated with sleep-wake variables, ESS and GHQ-12 scores, smoking and drinking habits, and academic performance. The areas under curve of ISI, AIS and SQI for detecting clinical insomnia were 0.85, 0.80 and 0.85, respectively. The optimal cut-offs for ISI, AIS and SQI were a total score of nine (sensitivity/specificity: 0.87/0.75), seven (sensitivity/specificity: 0.78/0.74) and five (sensitivity/specificity: 0.83/0.79), respectively.
  
  
  CONCLUSIONS
  The Chinese versions of ISI, AIS and SQI are reliable and valid instruments. The ISI and AIS appear to have better psychometric properties than the SQI.
authors.affiliation: Department of Psychiatry, University of Hong Kong, Hong Kong, China. kfchung@hkucc.hku.hk
authors.forename: Ka-Fai
authors.initials: KF
authors.lastname: Chung
authors.forename: Katherine Ka-Ki
authors.initials: KK
authors.lastname: Kan
authors.forename: Wing-Fai
authors.initials: WF
authors.lastname: Yeung
mesh_terms: D000293:Adolescent; D044466:Asian People; D002648:Child; D005260:Female; D006306:Health Surveys; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods / Q000592:standards; D011594:Psychometrics / Q000379:methods / Q000592:standards*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D012890:Sleep; D007319:Sleep Initiation and Maintenance Disorders / Q000175:diagnosis* / Q000523:psychology*; D011795:Surveys and Questionnaires / Q000592:standards; D055815:Young Adult