The Reliability and Validity of the Korean Version of the Medical Outcomes Study-Sleep Scale in Patients with Obstructive Sleep Apnea

• Main Authors: Min-Kyung Kim, Ji-Ae You, Jang-Han Lee, Sang-Ahm Lee
• Format: Article
• Language: English
• Published: Korean Society of Sleep Medicine 2011-12-01
• Series: Sleep Medicine Research
• Subjects: Medical Outcomes Study-Sleep Scale; Obstructive sleep apnea; Sleep quality; Reliability; Validity
• Online Access: http://www.sleepmedres.org/upload/pdf/smr-2-3-89.pdf
• ISSN: 2093-9175; 2233-8853

Background and Objective We developed a Korean version of the Medical Outcomes Study-Sleep Scale (MOS-Sleep) and confirmed its psychometric properties in patients with obstructive sleep apnea (OSA). Methods Data were collected from 735 patients with suspected OSA (82.9% male; mean age 47.86 years, range 18–84 years). We assessed internal consistency, test-retest reliabilities, factor analysis, multitrait scaling analysis, and concurrent validity. For assessing concurrent validity, patients were administered the Epworth Sleepiness Scale, Sleep Hygiene Index, Short Form-36 Health Survey (SF-36), Beck Depression Inventory (BDI), Multidimensional Fatigue Inventory (MFI), State-Trait Anxiety Inventory (STAI), and Sleep Disordered Breathing Symptom Questionnaire. Results Cronbach’s alpha coefficient for all domains and summary indices except Sleep Adequacy exceeded the 0.70 standard for internal consistency reliability. Test-retest reliability was acceptable (r = 0.47–0.87). Six factors were identified by factor analysis. These were the same as those in the original MOS-Sleep. Item convergent and discriminant validities were demonstrated in multi-item domains and indices. Correlations between the MOS-Sleep and other instruments administered in this study provided evidence for construct validity. The 9-item Sleep Problems Index-2 was significantly correlated with SF-36 (r = 0.575), MFI (r = 0.568), BDI (r = 0.499) and STAI (r = 0.435). MOS-Sleep was significantly correlated with subjective severity of OSA. Conclusions The Korean version of MOS-Sleep has internal consistency, test-retest reliability, and construct validity comparable with the original version.