title: The Epworth score in African American populations.
abstract: BACKGROUND
  African Americans have elevated scores on the Epworth Sleepiness Scale (ESS) compared to whites. The reason for this difference is not clear.
  
  
  METHODS
  Responses to the ESS were assessed in 687 patients (52.3% African American) referred to a hospital-based sleep clinic. Differences in total ESS score and the scores on individual Epworth questions were compared in African Americans and whites. Findings were validated in an independent sleep apnea research cohort of 712 subjects (57.3% African Americans).
  
  
  RESULTS
  African Americans in the clinic-based population had a higher mean ESS score than whites (11.4 +/- 0.3 vs. 9.8 +/- 0.3, p < 0.0001). This difference persisted after adjusting for sleepiness risk factors. In adjusted analyses including responses to the other ESS questions, African Americans scored significantly greater on 3 of the 8 ESS component questions: questions 2-"Watching TV," 6-"Sitting and talking to someone," and 7-"Sitting quietly after lunch without alcohol." In the validation cohort, African Americans also had a higher mean ESS score (9.1 +/- 0.3, vs. 8.2 +/- 0.3, p = 0.04). In addition they had significantly elevated scores on questions 6 and 7 (p = 0.0002, p = 0.012 respectively) even after adjusting for responses to the other Epworth questions.
  
  
  CONCLUSIONS
  African Americans have greater sleepiness than whites as assessed by the ESS; this is independent of sleepiness risk factors. The difference appears due primarily to differences in responses to questions 6 and 7 of the ESS questions suggesting a difference in the interpretation of these 2 questions.
authors.affiliation: Division of Pulmonary, Critical Care and Sleep Medicine, University Hospital Case Medical Center and Case Western Reserve University, Cleveland, OH, USA.
authors.forename: Amanda L
authors.initials: AL
authors.lastname: Hayes
authors.forename: James C
authors.initials: JC
authors.lastname: Spilsbury
authors.forename: Sanjay R
authors.initials: SR
authors.lastname: Patel
mesh_terms: D000328:Adult; D001741:Black or African American / Q000523:psychology; D006970:Disorders of Excessive Somnolence / Q000175:diagnosis* / Q000208:ethnology*; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008487:Medical History Taking; D008875:Middle Aged; D011594:Psychometrics; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires; D014481:United States / Q000453:epidemiology; D044465:White People / Q000523:psychology