title: American time use survey: sleep time and its relationship to waking activities.
abstract: OBJECTIVE
  To gain some insight into how various behavioral (lifestyle) factors influence sleep duration, by investigation of the relationship of sleep time to waking activities using the American Time Use Survey (ATUS).
  
  
  METHODS
  Cross-sectional data from ATUS, an annual telephone survey of a population sample of US citizens who are interviewed regarding how they spent their time during a 24-hour period between 04:00 on the previous day and 04:00 on the interview day.
  
  
  METHODS
  Data were pooled from the 2003, 2004, and 2005 ATUS databases involving N=47,731 respondents older than 14 years of age.
  
  
  METHODS
  N/A.
  
  
  RESULTS
  Adjusted multiple linear regression models showed that the largest reciprocal relationship to sleep was found for work time, followed by travel time, which included commute time. Only shorter than average sleepers (<7.5 h) spent more time socializing, relaxing, and engaging in leisure activities, while both short (<5.5 h) and long sleepers (> or =8.5 h) watched more TV than the average sleeper. The extent to which sleep time was exchanged for waking activities was also shown to depend on age and gender. Sleep time was minimal while work time was maximal in the age group 45-54 yr, and sleep time increased both with lower and higher age.
  
  
  CONCLUSIONS
  Work time, travel time, and time for socializing, relaxing, and leisure are the primary activities reciprocally related to sleep time among Americans. These activities may be confounding the frequently observed association between short and long sleep on one hand and morbidity and mortality on the other hand and should be controlled for in future studies.
authors.affiliation: Division of Sleep and Chronobiology, Department of Psychiatry, University of Pennsylvania School of Medicine, Philadelphia, PA 19104-6021, USA. basner@mail.med.upenn.edu
authors.forename: Mathias
authors.initials: M
authors.lastname: Basner
authors.forename: Kenneth M
authors.initials: KM
authors.lastname: Fomberstein
authors.forename: Farid M
authors.initials: FM
authors.lastname: Razavi
authors.forename: Siobhan
authors.initials: S
authors.lastname: Banks
authors.forename: Jeffrey H
authors.initials: JH
authors.lastname: William
authors.forename: Roger R
authors.initials: RR
authors.lastname: Rosa
authors.forename: David F
authors.initials: DF
authors.lastname: Dinges
mesh_terms: D000204:Activity Cycles; D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D001294:Attitude to Health; D006304:Health Status; D006801:Humans; D007899:Leisure Activities; D016014:Linear Models; D008875:Middle Aged; D017678:Sex Distribution; D012892:Sleep Deprivation / Q000453:epidemiology*; D012931:Social Environment; D011795:Surveys and Questionnaires; D014481:United States / Q000453:epidemiology; D014940:Work Schedule Tolerance