Past Issues

Objectives:To establish the validity of the Chinese version of the Athens Insomnia Scale (CAIS) and the diagnostic cutoff scores for insomnia. Methods:Two hundred and eighty-three subjects, consisting of 65 psychiatric outpatients and 218 non-clinical samples, completed the CAIS. The ICD-10 “nonorganic insomnia”was the diagnostic standard of insomnia, and the Insomnia Self-assessment Inventory (ISAI) was used as the external validator. Both the 8-item scale(CAIS-8) and the brief version containing the fi rst 5 items (CAIS-5) were analyzed. Results: In both versions, the Cronbach's α of internal consistency reached 0.82-0.84. Correlation coeffi cients of test-retest reliability were 0.84-0.86. The correlation coeffi cients between the CAIS and ISAI were 0.72-0.76. The CAIS-8 demonstrated two components in factor analysis: items 1 to 5 (nighttime symptoms)and items 6 to 8 (daytime symptoms). The suggested cutoff points for insomnia among this ethnic Chinese population are 8 for the CAIS-8 (AUC=0.89,p<0.01) and 5 for the CAIS-5 (AUC=0.90, p<0.01), respectively. Conclusion:The CAIS-8 and CAIS-5 are fair tools in screening and making insomnia diagnoses in clinical practice, and have satisfactory reliability and validity.