Validation of the Japanese version of the Sleep Hygiene Practice Scale.

OBJECTIVE This study sought to validate the Japanese version of the Sleep Hygiene Practices Scale (SHPS-J). PATIENTS/METHODS A cross-sectional questionnaire-based study was conducted via the internet. In total, 854 participants (435 men, 419 women; mean age, 42.91 ± 11.54 years) were asked to complete all scales, and 283 of them were asked to complete the same scales two weeks later. The survey consisted of the SHPS-J, the Japanese version of the Insomnia Severity Index (ISI-J), and the Japanese version of the Pittsburgh Sleep Quality Index (PSQI-J). The SHPS-J was developed according to the International Society for Pharmacoeconomics and Outcomes Research Task Force for Translation and Cultural Adaption. For the analysis, participants were divided into three groups: insomnia syndrome, insomnia symptoms, and good sleep groups. RESULTS The SHPS-J had good test-retest reliability (ICC: 0.55-0.76) and adequate internal consistency (α = 0.54-0.74), except with regard to eating/drinking behaviors. The factorial validity of the four-factor structure was confirmed through a confirmatory factor analysis; however, one item related to eating/drinking behaviors had no significant factor loading. The construct validity was confirmed through a correlation analysis between each domain of the SHPS-J and ISI-J (r = 0.19-0.60, p < 0.01). The results of clinical validation confirmed that all domains of the SHPS-J were significantly higher for individuals with insomnia than for good sleepers. CONCLUSIONS This study confirmed both the reliability and validity of the SHPS-J.