title: Reliability and validity of the Pittsburgh Sleep Quality Index and the Epworth Sleepiness Scale in older men.
abstract: BACKGROUND
  The Pittsburgh Sleep Quality Index (PSQI) and the Epworth Sleepiness Scale (ESS) are commonly used to quantify sleep and excessive daytime sleepiness in older adults. These measures, however, have not been comprehensively evaluated for their psychometrics in older men. We determined the internal consistency reliability and construct validity of the PSQI and ESS in a sample of older men.
  
  
  METHODS
  Participants were 3,059 men (mean age = 76.4 years) in the Osteoporotic Fractures in Men Study (MrOS) who completed the two questionnaires, wrist actigraphy, and a range of additional psychosocial and health measures.
  
  
  RESULTS
  Internal consistency was adequate for the PSQI (Cronbach's α =.69) and the ESS (α = .70) total scores. PSQI daytime dysfunction and sleep medications components were weakly associated with the total score, but their removal did not notably improve internal consistency. PSQI and ESS totals were associated with each other and with theoretically related variables (ie, actigraphic variables, depressive symptoms, mobility/instrumental activities of daily living, health-related quality of life) in expected directions. The PSQI differentiated participants reporting no sleep disorder from those reporting particular disorders more reliably than the ESS.
  
  
  CONCLUSIONS
  In general, we found evidence of the internal consistency reliability and construct validity of the PSQI and ESS in older men. Despite low correlation with the PSQI global score, the PSQI daytime dysfunction and sleep medications components do not appreciably reduce the PSQI total score's reliability or validity in older men.
authors.affiliation: Department of Mental Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA. aspira@jhsph.edu
authors.forename: Adam P
authors.initials: AP
authors.lastname: Spira
authors.forename: Sherry A
authors.initials: SA
authors.lastname: Beaudreau
authors.forename: Katie L
authors.initials: KL
authors.lastname: Stone
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Kezirian
authors.forename: Li-Yung
authors.initials: LY
authors.lastname: Lui
authors.forename: Susan
authors.initials: S
authors.lastname: Redline
authors.forename: Sonia
authors.initials: S
authors.lastname: Ancoli-Israel
authors.forename: Kristine
authors.initials: K
authors.lastname: Ensrud
authors.forename: Anita
authors.initials: A
authors.lastname: Stewart
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D003863:Depression / Q000453:epidemiology; D006801:Humans; D006993:Hypnotics and Sedatives / Q000627:therapeutic use; D008297:Male; D015995:Prevalence; D011788:Quality of Life; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D007319:Sleep Initiation and Maintenance Disorders / Q000188:drug therapy / Q000453:epidemiology*; D011795:Surveys and Questionnaires
chemical_list: D006993:Hypnotics and Sedatives