title: Sleep and need for recovery in shift workers: do chronotype and age matter?
abstract: This study examined associations of chronotype and age with shift-specific assessments of main sleep duration, sleep quality and need for recovery in a cross-sectional study among N = 261 industrial shift workers (96.6% male). Logistic regression analyses were used, adjusted for gender, lifestyle, health, nap behaviour, season of assessment and shift schedule. Shift workers with latest versus earliest chronotype reported a shorter sleep duration (OR 11.68, 95% CI 3.31-41.17) and more awakenings complaints (OR 4.84, 95% CI 4.45-11.92) during morning shift periods. No associations were found between chronotype, sleep and need for recovery during evening and night shift periods. For age, no associations were found with any of the shift-specific outcome measures. The results stress the importance of including the concept of chronotype in shift work research and scheduling beyond the concept of age. Longitudinal research using shift-specific assessments of sleep and need for recovery are needed to confirm these results.
  Chronotype seems to better explain individual differences in sleep than age. In view of ageing societies, it might therefore be worthwhile to further examine the application of chronotype for individualised shift work schedules to facilitate healthy and sustainable employment.
authors.affiliation: a Division of Community and Occupational Medicine, Department of Health Sciences , University Medical Center Groningen, University of Groningen , Groningen , The Netherlands.
authors.forename: Hardy A
authors.initials: HA
authors.lastname: van de Ven
authors.affiliation: a Division of Community and Occupational Medicine, Department of Health Sciences , University Medical Center Groningen, University of Groningen , Groningen , The Netherlands.
authors.forename: Jac J L
authors.initials: JJ
authors.lastname: van der Klink
authors.affiliation: b Channing Division of Network Medicine, Brigham and Women's Hospital and Harvard Medical School , Boston , MA , USA.|c Institute of Medical Psychology, Ludwig Maximilian University Munich , Munich , Germany.
authors.forename: Céline
authors.initials: C
authors.lastname: Vetter
authors.affiliation: c Institute of Medical Psychology, Ludwig Maximilian University Munich , Munich , Germany.
authors.forename: Till
authors.initials: T
authors.lastname: Roenneberg
authors.affiliation: d Chronobiology Unit, GELIFES, University of Groningen , Groningen , The Netherlands.
authors.forename: Marijke
authors.initials: M
authors.lastname: Gordijn
authors.affiliation: a Division of Community and Occupational Medicine, Department of Health Sciences , University Medical Center Groningen, University of Groningen , Groningen , The Netherlands.
authors.forename: Wendy
authors.initials: W
authors.lastname: Koolhaas
authors.affiliation: e TNO , Leiden , The Netherlands.|f Department of Human Movement Sciences , VU University , Amsterdam , The Netherlands.
authors.forename: Michiel P
authors.initials: MP
authors.lastname: de Looze
authors.affiliation: a Division of Community and Occupational Medicine, Department of Health Sciences , University Medical Center Groningen, University of Groningen , Groningen , The Netherlands.
authors.forename: Sandra
authors.initials: S
authors.lastname: Brouwer
authors.affiliation: a Division of Community and Occupational Medicine, Department of Health Sciences , University Medical Center Groningen, University of Groningen , Groningen , The Netherlands.
authors.forename: Ute
authors.initials: U
authors.lastname: Bültmann
mesh_terms: D000328:Adult; D000367:Age Factors; D057906:Circadian Clocks / Q000502:physiology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007221:Industry; D008297:Male; D008875:Middle Aged; D009784:Occupational Diseases / Q000209:etiology / Q000503:physiopathology; D020127:Recovery of Function / Q000502:physiology*; D012890:Sleep / Q000502:physiology*; D020178:Sleep Disorders, Circadian Rhythm / Q000209:etiology / Q000503:physiopathology; D013997:Time Factors; D014851:Wakefulness; D014940:Work Schedule Tolerance / Q000502:physiology*
keywords: Munich Chronotype Questionnaire; circadian rhythm; shift work; work schedule tolerance