STRENGTHS AND LIMITATIONS OF THIS STUDY

  • The adequately powered sample and minimal missing data are study strengths.

  • The study sample closely reflects the National Health Service workforce, thereby supporting the generalisability and validity of the findings.

  • The survey study design, use of convenience sampling and targeted recruitment of shift workers with sleep problems may have introduced selection bias.

  • In addition, the cross-sectional design does not allow conclusions to be drawn about the directionality or causality of the observed associations.

  • The Shift Work Disorder Index used to define shift work disorder (SWD) is a screening tool and hence a definite diagnosis of SWD could not be made.

    • Introduction

    Working non-standard hours (defined as work scheduled after 18:00 or before 7:00) is common in healthcare, transportation, hospitality and manufacturing sectors. This includes nights, early morning, late evening and rotating shifts. According to…