title: Circadian type and bed-timing regularity in 654 retired seniors: correlations with subjective sleep measures.
abstract: OBJECTIVE
  Using telephone interview data from retired seniors to explore how inter-individual differences in circadian type (morningness) and bed-timing regularity might be related to subjective sleep quality and quantity.
  
  
  METHODS
  MANCOVA with binary measures of morningness, stability of bedtimes, and stability of rise-times as independent variables; sleep measures as dependent variables; age, former shift work, and gender as covariates.
  
  
  METHODS
  Telephone interviews using a pseudo-random age-targeted sampling process.
  
  
  METHODS
  654 retired seniors (65 y+, 363M, 291F).
  
  
  METHODS
  none.
  
  
  RESULTS
  
  
  
  METHODS
  (1) circadian type (from Composite Scale of Morningness [CSM]), and stability of (2) bedtime and (3) rise-time from the Sleep Timing Questionnaire (STQ).
  
  
  METHODS
  Pittsburgh Sleep Quality Index (PSQI) score, time in bed, time spent asleep, and sleep efficiency, from Sleep Timing Questionnaire (STQ). Morning-type orientation, stability in bedtimes, and stability in rise-times were all associated with better sleep quality (P < 0.001, for all; effect sizes: 0.43, 0.33, and 0.27). Morningness was associated with shorter time in bed (P < 0.0001, effect size 0.45) and time spent asleep (P < 0.005, effect size 0.26). For bedtime and rise-time stability the direction of effect was similar but mostly weaker.
  
  
  CONCLUSIONS
  In retired seniors, a morning-type orientation and regularity in bedtimes and rise-times appear to be correlated with improved subjective sleep quality and with less time spent in bed.
authors.affiliation: Neuroscience Clinical and Translational Research Center, Western Psychiatric Institute and Clinic, University of Pittsburgh Medical Center, 3811 O'Hara Street, Pittsburgh, PA 15213, USA. monkth@upmc.edu
authors.forename: Timothy H
authors.initials: TH
authors.lastname: Monk
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Buysse
authors.forename: Bart D
authors.initials: BD
authors.lastname: Billy
authors.forename: Mary E
authors.initials: ME
authors.lastname: Fletcher
authors.forename: Kathy S
authors.initials: KS
authors.lastname: Kennedy
authors.forename: Janet E
authors.initials: JE
authors.lastname: Schlarb
authors.forename: Scott R
authors.initials: SR
authors.lastname: Beach
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D002940:Circadian Rhythm / Q000502:physiology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007407:Interviews as Topic; D008297:Male; D012179:Retirement; D012890:Sleep / Q000502:physiology*; D011795:Surveys and Questionnaires