# Associations between shift work characteristics and work-related accidents and dozing off: combining objective working-time register and retrospective survey data

## TL;DR

This study found that certain shift work patterns, like quick returns and long shifts, are linked to higher risks of work-related accidents and dozing off among healthcare workers.

## Contribution

The study combines objective working-time data with self-reported outcomes to analyze the impact of shift work characteristics on safety and fatigue.

## Key findings

- Quick returns and long shifts were associated with increased risk of self-harm and harm to patients or equipment.
- Night shifts were linked to dozing off at work and during commutes.
- Day and evening shifts were associated with lower risk of harming patients or others.

## Abstract

This study investigated the associations between shift work characteristics and self-reported work-related accidents, as well as incidents of dozing off at work and during the work commute.

Data from a Norwegian hospital’s working-time register encompassed information on quick returns (<11 hours between shifts), day-, evening-, night-, and long (≥12 hours) shifts worked during 2020, and were linked to questionnaire data from 1195 healthcare workers collected in January 2021. The questionnaire assessed work-related accidents causing harm to oneself, patients/others, and/or equipment the last year, as well as dozing off at work the last month and/or during commute the last year. Data were analyzed using negative binomial regressions, adjusting for age, sex, children, marital status, shift work experience, monthly working hours, circadian type, and night shifts.

Number of quick returns the last year was positively associated with causing harm to oneself [incidence rate ratio (IRR) 1.021, 95% confidence interval (CI) 1.009–1.034]. Number of day shifts and evening shifts were negatively associated with causing harm to patients/others (IRR 0.987, 95% CI 0.981–0.992; IRR 0.989, 95% CI 0.982–0.996, respectively). Number of night shifts was positively associated with dozing off at work (IRR 1.005, 95% CI 1.002–1.008) and during commute (IRR 1.007, 95% CI 1.003–1.010), but was not associated with work-related accidents. Number of long shifts was positively associated with healthcare workers causing harm to oneself (IRR 1.198, 95% CI 1.111–1.291), patients/others (IRR 1.209, 95% CI 1.122–1.304), and equipment (IRR 1.174, 95% CI 1.080–1.275).

Limiting quick returns and long shifts may be relevant considerations for improving employee and patient safety.