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.

Practitioner Summary: 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.

Keywords::

• work schedule tolerance
• Munich Chronotype Questionnaire
• shift work
• circadian rhythm

Acknowledgements

We would like to thank Martha Merrow for building bridges between disciplines and her thoughtful contributions to the translations of the MCTQ^Shift.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This study was financially supported by a grant of ZonMw [grant number 208020004]. The funding agency did not play any part in designing the research protocol, data analyses, data interpretation or writing of the report. All authors contributed to the initiation of the study, study design, conduct of the study, analysis and interpretation of data, and preparation of the manuscript.