A case-control study of sleep-related factors and occupational injuries at an Italian teaching hospital

Abstract

Background: Sleep disorders have been associated with increased risk of occupational injuries in various settings. Purpose: We investigated the associations between sleep, daytime sleepiness, and chronotype (preference for morning or evening activities) and the risk of occupational injuries in an Italian teaching hospital. Methods: A case-control study of employees of the University Hospital of Udine, Italy, was conducted on 200 employees reporting occupational injuries and 183 controls. Information was collected on usual sleep quantity and quality. Sleepiness was assessed with the Epworth Sleepiness Scale. Chronotype was assessed with the Horne–Ostberg morningness–eveningness questionnaire. The association of sleep-related exposures with the risk of injury was assessed with multivariate unconditional logistic regression, adjusting for potentially confounding individual characteristics. Results: Among sleep-related variables, the number of reported sleep disturbances was positively related with occupational injuries, whereas daytime sleepiness was inversely associated with injuries. Cases had shorter usual sleep hours than controls, although the difference was not statistically significant. No association was found between usual sleep hours and injuries. Chronotype was not significantly associated with injury, although we observed a decreasing trend in risk of injury from morning to evening chronotypes. Conclusions: Self-reported sleep disturbance was positively associated with increased risk of occupational injury in an Italian hospital. However, contrary to expectation, daytime sleepiness was inversely related to injuries.

Keywords:

• occupational injuries
• morningness–eveningness questionnaire
• teaching hospital
• sleepiness
• case-control study

Acknowledgement

We thank Dr Cristina Caffau for inspiring us to take up this project.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Italian Ministry of Health through the Ricerca Finalizzata Bando Giovani Ricercatori 2009 [GR-2009-1569913].

Notes on contributors

Francesca Valent

Francesca Valent, MD, MSPH, PhD, is an epidemiologist in the Regional Health Directorate of Friuli Venezia Giulia and in the Institute of Hygiene and Clinical Epidemiology of the University Hospital of Udine, Italy.

Giulia Liva

Giulia Liva, MA, is an administrative assistant in the Institute of Hygiene and Clinical Epidemiology and in the Rare Diseases Center of the University Hospital of Udine, Italy.

Marika Mariuz

Marika Mariuz, BSc, PhD, is a biologist in the Institute of Hygiene and Clinical Epidemiology of the University Hospital of Udine, Italy.

Fabrizio Bellomo

Fabrizio Bellomo, BSHP, is health professions specialist in the Clinical Risk Unit of the University Hospital of Udine, Italy.

Daniela De Corti

Daniela De Corti, BSN, GradCertRiskMg , is a nurse in the Clinical Risk Unit of the University Hospital of Udine, Italy.

Stefania Degan

Stefania Degan, BSN, GradCertRiskMg , is a nurse in the Clinical Risk Unit of the University Hospital of Udine, Italy.

Pierluigi Dolso

Pierluigi Dolso, MD, is a neurologist in the University Hospital of Udine, Italy.

Fabio Barbone

Fabio Barbone, MD, DrPH, is a professor of Hygiene in the School of Medicine of the University of Udine, and the director of the Institute of Hygiene and Clinical Epidemiology of the University Hospital of Udine, Italy.

Gian Luigi Gigli

Gian Luigi Gigli, MD, is a professor of Neurology in the University Hospital of Udine, Italy.

Silvio Brusaferro

Silvio Brusaferro, MD, is a professor of Hygiene in the School of Medicine of the University of Udine, and the director of the Clinical Risk Unit of the University Hospital of Udine, Italy.