Quality of life, depression, and productivity of city government employees in Japan: a comparison study using the Athens insomnia scale and insomnia severity index

Abstract

Insomnia has a high prevalence in modern society. Various tools have been developed to assess insomnia. We performed a direct comparison between the Insomnia Severity Index (ISI) and the Athens Insomnia Scale (AIS) in a Japanese population. A cross-sectional questionnaire-based study was conducted in September 2017 as part of the Night in Japan Home Sleep Monitoring Study. In addition to insomnia, assessed using the AIS and ISI, depression, sleepiness, quality of life, and work performance were assessed using the Patient Health Questionnaire (PHQ)-9, a Japanese version of the Epworth Sleepiness Scale, the Short Form-8 Health Survey Questionnaire (SF-8), and the World Health Organization Health and Work Performance Questionnaire, respectively. Receiver operating characteristic (ROC) curves were constructed to compare the outcomes of the AIS and the ISI. A total of 1685 (81.9%) of all eligible employees were enrolled. The total scores of the AIS and ISI had a Pearson correlation coefficient (r) of 0.80 (p < 0.01). The area under the ROC curve for the AIS and ISI for the detection of depression (PHQ-9 ≥ 10) was 0.89 and 0.86, respectively. The prevalence of clinical insomnia (ISI ≥ 15) and definite insomnia (AIS ≥ 10) were 6.5 and 10.8%, respectively. Both the AIS and ISI showed a weak negative correlation with the physical component summary score of the SF-8 (r = − 0.37, p < 0.01 and r = − 0.32, p < 0.01, respectively) and absolute presenteeism (r = − 0.32, p < 0.01 and r = − 0.28, p < 0.01, respectively) and a moderate negative correlation with the mental component summary score of the SF-8 (r = − 0.53, p < 0.01 and r = − 0.43, p < 0.01, respectively). A strong positive correlation was found between the total scores of the AIS and ISI. Both the AIS and ISI were found to be associated with low physical and mental quality of life, depression, and productivity loss at work. Moreover, they had a moderate accuracy for detecting depression. Both the AIS and ISI may serve as useful screening tools for both insomnia and depression in the Japanese working population. UMIN-CTR (UMIN000028675, registered on 2017/8/15) and ClinicalTrials.gov ( NCT03276585 , registered on 2017/9/3).