ABSTRACT
OBJECTIVES: Bedtime procrastination is defined as going to bed later than intended, without having external reasons for doing so. Despite various studies investigating the new concept of bedtime procrastination, there have been no studies that have validated the Bedtime Procrastination Scale (BPS). Thus, this study aims to validate the BPS in Korean. METHODS: Two hundred twenty seven participants (mean age 22±2.39 years, 81.1% female) participated in the study. All participants completed the BPS, Insomnia Severity Index, Center for Epidemiologic Studies Depression Scale, Perceived Stress Scale, Depressive Symptom Inventory-Suicidality Subscale, and General Procrastination Scale (GPS). Exploratory factor analysis was used to determine number of factors. RESULTS: Exploratory factor analysis revealed support for one factor, which was consistent with the original study. Goodness of fit was adequate for the one factor model [χ²=59.369(df=27, p<0.001), Comparative Fit Index=0.963, Tucker-Lewis Index=0.951, Root Mean Square Error of Approximation= 0.073, Standardized Root Mean Square Residual=0.042]. Internal consistency was also adequate (Cronbach's alpha=0.86). Convergent validity was also high with the GPS (p<0.001, r=0.411). Correlations were also high with other questionnaires (p<0.05). CONCLUSIONS: The BPS is a reliable and valid measure for bedtime procrastination, and may have important clinical implications for sleep disorders.