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Mediating pathways and gender differences between shift work and subjective cognitive function
  1. Imelda S Wong1,
  2. Peter M Smith2,3,
  3. Selahadin Ibrahim2,
  4. Cameron A Mustard2,3,
  5. Monique A M Gignac2,3
  1. 1National Institute for Occupational Safety and Health, Cincinnati, Ohio, USA
  2. 2Institute for Work and Health, Toronto, Ontario, Canada
  3. 3Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada
  1. Correspondence to Dr Imelda S Wong, Division of Applied Research and Technology, National Institute for Occupational Safety and Health, 1150 Tusculum Ave, MS C-24, Cincinnati, OH 452226, USA; IWong{at}


Objectives Increased injury risk among shift workers is often attributed to cognitive function deficits that come about as a result of sleep disruptions. However, little is known about the intermediate influences of other factors (eg, work stress, health) which may affect this relationship. In addition, gender differences in these the complex relationships have not been fully explored. The purpose of this study is to (1) identify the extent to which work and non-work factors mediate the relationship between shift work, sleep and subsequent subjective cognitive function; and (2) determine if the mediating pathways differ for men and women.

Methods Data from the 2010 National Population Health Survey was used to create a cross-sectional sample of 4255 employed Canadians. Using path modelling, we examined the direct and indirect relationships between shift work, sleep duration, sleep quality and subjective cognitive function. Multigroup analyses tested for significantly different pathways between men and women. Potential confounding effects of age and self-reported health and potential mediating effects of work stress were simultaneously examined.

Results Work stress and sleep quality significantly mediated the effects of shift work on cognition. Age and health confounded the relationship between sleep quality and subjective cognition. No differences were found between men and women.

Conclusions Occupational health and safety programmes are needed to address stress and health factors, in addition to sleep hygiene, to effectively address cognitive function among shift workers.

  • path analyses
  • subjective cognitive function

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  • Contributors ISW conceptualised the study idea, developed the study design, and performed data analyses and interpretation. PMS and MAMG contributed to study design, data analyses and interpretation. SI contributed to data analyses and interpretation. CAM contributed to data acquisition and data interpretation. All authors contributed to the editorial preparation of this paper.

  • Funding Funding for ISW was provided by the Mustard Post-doctoral Fellowship from the Institute for Work & Health (IWH), and the Oak Ridge Institute for Science and Education (ORISE) through an interagency agreement with the National Institute for Occupational Safety and Health (NIOSH). PMS is supported by a Chair in Gender, Work & Health from the Canadian Institutes of Health Research. IWH operates with the support of the Province of Ontario.

  • Disclaimer The views expressed in this document are those of the authors and do not necessarily reflect those of the Province of Ontario or ORISE.

  • Competing interests None declared.

  • Ethics approval Ethical approval for this study was obtained through the University of Toronto, Health Sciences' Ethics Committee.

  • Provenance and peer review Not commissioned; externally peer reviewed.