Purpose: The purposes of this study were to develop a Minimal Insomnia Screening Scale for Korean adults (KMISS) and to evaluate psychometric properties and discriminant ability of the developed scale.
Methods: Data from a cross-sectional survey of 959 Korean adults were analyzed to develop the summated insomnia scale, which was evaluated in terms of reliability, validity, and discriminant ability by receiver operating characteristics (ROC) curve analysis.
Results: Item-total correlations ranged between .71-.79 and Cronbach's α was .87. Adequate validity was also evident. ROC-curve analysis showed area under ROC was .87 (95% CI: .84-.90) and identified the optimal cut-off score as ≤ 20 (sensitivity, .83; specificity, .75; positive/negative predictive values, .40/.95). Using this cut-off score, the prevalence of insomnia in the study sample was 26.3% and most frequent among women and the oldest group.
Conclusion: Data supports the psychometric properties of KMISS as a possible insomnia screening instrument. KMISS also shows promise as a convenient ultra-short screening measure of insomnia for adults and epidemiological studies in community health care settings.
Keywords: Psychometrics; Questionnaire; Self-report; Sleep.