The reliability and validity of the Korean version of the Epworth sleepiness scale

• Published in: Sleep & breathing Vol. 15; no. 3; pp. 377 - 384
• Main Authors: Cho, Yong Won, Lee, Joo Hwa, Son, Hyo Kyung, Lee, Seung Hoon, Shin, Chol, Johns, Murray W.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.09.2011; Springer; Springer Nature B.V
• Subjects: Adult; Biological and medical sciences; Body Mass Index; Cross-Cultural Comparison; Dentistry; Disorders of Excessive Somnolence - diagnosis; Disorders of higher nervous function. Focal brain diseases. Central vestibular syndrome and deafness. Brain stem syndromes; Female; Fundamental and applied biological sciences. Psychology; Humans; Internal Medicine; Investigative techniques of ocular function and vision; Investigative techniques, diagnostic techniques (general aspects); Korea; Male; Medical sciences; Medical screening; Medicine; Medicine & Public Health; Middle Aged; Nervous system (semeiology, syndromes); Neurology; Original Article; Otorhinolaryngology; Pediatrics; Pneumology/Respiratory System; Polysomnography; Psychometrics - statistics & numerical data; Reference Values; Reliability; Reproducibility of Results; Sleep Apnea, Obstructive - diagnosis; Sleep disorders; Sleep. Vigilance; Snoring - diagnosis; Surveys and Questionnaires; Translating; Validity; Vertebrates: nervous system and sense organs; Korea; Validity; Reliability; Sleep-disordered breathing; Epworth sleepiness scale; Nervous system diseases; Sleep apnea syndrome; Sleep; Respiratory disease; Sleep disorder; Korean; Sleep wake cycle; Neurological disorder
• ISSN: 1520-9512; 1522-1709; 1522-1709
• DOI: 10.1007/s11325-010-0343-6

Objective The Epworth sleepiness scale (ESS) is widely used to measure the subject's average sleep propensity across those different situations in daily life, particularly in patients with sleep-disordered breathing. The purposes of this study were to test the hypothesis that the Korean version of the ESS (KESS) is valid and evaluate its usefulness. Materials and methods We developed the KESS, which involved translating into Korean and then translating back into English to check its accuracy. A total of 273 participants (181 obstructive sleep apnea (OSA)—37 mild, 61 moderate, 83 severe, 32 simple snoring and 60 normal) were included in this study. All subjects completed the overnight polysomnograph and 53 of the total subjects were randomly selected for a retest with the questionnaire approximately 2∼4 weeks later. The associations between KESS and the degree of OSA were examined through ANCOVA, adjusted for age, sex and BMI . Results The total score and each item's score of KESS in patients with OSA were significantly higher than subjects with normal controls ( p  < 0.01). As the severity of OSA increased, the KESS showed significantly increasing patterns ( p for trend <0.01). The KESS in patient groups showed good internal consistency (Cronbach's α  = 0.90) and test–retest reliability ( r  = 0.78 to 0.93). Conclusion The KESS is a reliable and valid tool for screening patients with daytime sleepiness in Korea.