title: Do obesity and sleep problems cluster in the workplace? A multivariate, multilevel study.
abstract: OBJECTIVE
  The aim of this study was to examine the co-occurrence of obesity and sleep problems among employees and workplaces.
  
  
  METHODS
  We obtained data from 39 873 men and women working in 3040 workplaces in 2000-2002 (the Finnish Public Sector Study). Individual- and workplace-level characteristics were considered as correlates of obesity and sleep problems, which were modelled simultaneously using a multivariate, multilevel approach.
  
  
  RESULTS
  Of the participants, 11% were obese and 23% reported sleep problems. We found a correlation between obesity and sleep problems at both the individual [correlation coefficient 0.048, covariance 0.047, standard error (SE) 0.005) and workplace (correlation coefficient 0.619, covariance 0.068, SE 0.011) level. The latter, but not the former, correlation remained after adjustment for individual- and workplace-level confounders, such as age, sex, socioeconomic status, shift work, alcohol consumption, job strain, and proportion of temporary employees and manual workers at the workplace.
  
  
  CONCLUSIONS
  Obese employees and those with sleep problems tend to cluster in the same workplaces, suggesting that, in addition to targeting individuals at risk, interventions to reduce obesity and sleep problems might benefit from identifying "risky" workplaces.
authors.affiliation: Finnish Institute of Occupational Health, Lemminkäisenkatu 14-18 B, FIN-20520 Turku, Finland. tuula.oksanen@ttl.fi.
authors.forename: Tuula
authors.initials: T
authors.lastname: Oksanen
authors.forename: Ichiro
authors.initials: I
authors.lastname: Kawachi
authors.forename: S V
authors.initials: SV
authors.lastname: Subramanian
authors.forename: Daniel
authors.initials: D
authors.lastname: Kim
authors.forename: Kokoro
authors.initials: K
authors.lastname: Shirai
authors.forename: Anne
authors.initials: A
authors.lastname: Kouvonen
authors.forename: Jaana
authors.initials: J
authors.lastname: Pentti
authors.forename: Paula
authors.initials: P
authors.lastname: Salo
authors.forename: Marianna
authors.initials: M
authors.lastname: Virtanen
authors.forename: Jussi
authors.initials: J
authors.lastname: Vahtera
authors.forename: Mika
authors.initials: M
authors.lastname: Kivimäki
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D015897:Comorbidity; D005260:Female; D005387:Finland / Q000453:epidemiology; D006306:Health Surveys; D006801:Humans; D008297:Male; D017533:Marital Status; D008875:Middle Aged; D015999:Multivariate Analysis; D009765:Obesity / Q000453:epidemiology*; D009784:Occupational Diseases / Q000453:epidemiology*; D015995:Prevalence; D012737:Sex Factors; D012893:Sleep Wake Disorders / Q000453:epidemiology*; D012923:Social Class; D013315:Stress, Psychological / Q000453:epidemiology; D017132:Workplace / Q000706:statistics & numerical data; D055815:Young Adult