title: Use of the Epworth Sleepiness Scale in Chinese patients with obstructive sleep apnea and normal hospital employees.
abstract: OBJECTIVE
  To determine the use of the Epworth Sleepiness Scale (ESS) in Chinese patients with obstructive sleep apnea syndrome (OSA) and normal hospital employees.
  
  
  METHODS
  Our sample consisted of 61 healthy controls and 100 patients with OSA. The test-retest reliability, internal consistency, and concurrent validity of the Chinese version of the ESS were analyzed. We also compared the ESS scores between controls and patients, studied the association between the ESS score and the apnea-hypopnea index (AHI) and minimum oxygen saturation (mO(2)), and examined to what extent the ESS score was predictive of mean sleep latency of the Multiple Sleep Latency Test (MSLT).
  
  
  RESULTS
  The Chinese version of the ESS was found to have satisfactory reliability and validity. The mean+/-S.D. of ESS scores in normals was 7.5+/-3.0; in patients, it was 13.2+/-4.7. The ESS score had a negative association with mean sleep latency of the MSLT (rho=-0.42, P=0.0001) but no correlation with the AHI and mO(2). ESS scores of 14 and above significantly predicted a low mean sleep latency of the MSLT.
  
  
  CONCLUSIONS
  The ESS should be included as one of the methods for assessing sleepiness in clinic samples of patients with OSA. Our data showed that the ESS was useful to separate patients with and without pathological degree of objective daytime sleepiness as determined by the MSLT.
authors.affiliation: Department of Psychiatry, Queen Mary Hospital, The University of Hong Kong, 102 Pokfulam Road, SAR, Hong Kong, China. kfchung@hkucc.hku.hk
authors.forename: K F
authors.initials: KF
authors.lastname: Chung
mesh_terms: D000328:Adult; D000368:Aged; D002681:China / Q000208:ethnology; D006970:Disorders of Excessive Somnolence / Q000175:diagnosis / Q000208:ethnology / Q000209:etiology; D005260:Female; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010564:Personnel, Hospital; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D020181:Sleep Apnea, Obstructive / Q000150:complications* / Q000175:diagnosis / Q000208:ethnology; D011795:Surveys and Questionnaires