title: Trends and determinants of time in bed in Geneva, Switzerland.
abstract: OBJECTIVE
  There is limited information regarding sleep duration and determinants in Switzerland. We aimed to assess the trends and determinants of time in bed as a proxy for sleep duration in the Swiss canton of Geneva.
  
  
  METHODS
  Data from repeated, independent cross-sectional representative samples of adults (≥ 18 years) of the Geneva population were collected between 2005 and 2011. Self-reported time in bed, education, monthly income, and nationality were assessed by questionnaire.
  
  
  RESULTS
  Data from 3,853 participants (50% women, 51.7 ± 10.9 years) were analyzed. No significant trend was observed between 2005 and 2011 regarding time in bed or the prevalence of short (≤ 6 h/day) and long (> 9 h/day) time in bed. Elderly participants reported a longer time in bed (year-adjusted mean ± standard error: 7.67 ± 0.02, 7.82 ± 0.03, and 8.41 ± 0.04 h/day for 35-50, 50-65, and 65+ years, respectively, p < 0.001), while shorter time in bed was reported by non-Swiss participants (7.77 ± 0.03 vs. 7.92 ± 0.03 h/day for Swiss nationals, p < 0.001), participants with higher education (7.92 ± 0.02 for non-university vs. 7.74 ± 0.03 h/day for university, p < 0.001) or higher income (8.10 ± 0.04, 7.84 ± 0.03, and 7.70 ± 0.03 h/day for < 5,000 SFr; 5,000-9,500 SFr, and > 9,500 SFr, respectively, p < 0.001). Multivariable-adjusted polytomous logistic regression showed short and long time in bed to be positively associated with obesity and negatively associated with income.
  
  
  CONCLUSIONS
  In a Swiss adult population, sleep duration as assessed by time in bed did not change significantly between 2005 and 2011. Both clinical and socioeconomic factors influence time in bed.
authors.affiliation: Institute of Social and Preventive Medicine (IUMSP), Lausanne University Hospital, Lausanne, Switzerland.
authors.forename: Cédric
authors.initials: C
authors.lastname: Gubelmann
authors.affiliation: Institute of Social and Preventive Medicine (IUMSP), Lausanne University Hospital, Lausanne, Switzerland ; Unit of Population Epidemiology, Division of Primary Care Medicine, Department of Community Medicine and Primary Care and Emergency Medicine, Geneva University Hospitals, Geneva, Switzerland.
authors.forename: Idris
authors.initials: I
authors.lastname: Guessous
authors.affiliation: Unit of Population Epidemiology, Division of Primary Care Medicine, Department of Community Medicine and Primary Care and Emergency Medicine, Geneva University Hospitals, Geneva, Switzerland.
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Theler
authors.affiliation: Center for Investigation and Research in Sleep, Lausanne University Hospital, Lausanne, Switzerland.
authors.forename: José
authors.initials: J
authors.lastname: Haba-Rubio
authors.affiliation: Unit of Population Epidemiology, Division of Primary Care Medicine, Department of Community Medicine and Primary Care and Emergency Medicine, Geneva University Hospitals, Geneva, Switzerland.
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Gaspoz
authors.affiliation: Institute of Social and Preventive Medicine (IUMSP), Lausanne University Hospital, Lausanne, Switzerland ; Department of Internal Medicine, Internal Medicine, Lausanne University Hospital, Lausanne, Switzerland.
authors.forename: Pedro
authors.initials: P
authors.lastname: Marques-Vidal
mesh_terms: D000367:Age Factors; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007182:Income; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D057566:Self Report; D012890:Sleep; D012892:Sleep Deprivation / Q000453:epidemiology*; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires; D013557:Switzerland / Q000453:epidemiology; D013997:Time Factors
keywords: Switzerland.; adult; population-based study; sleep; socioeconomic status; trends