Understanding the effect of occupational stress on sleep quality in firefighters: the modulating role of depression and burnout.

Objectives: Sleep quality of firefighters can be negatively affected by occupational stressors. A cross-sectional investigation was conducted to understand how work-related stress, post-traumatic stress, burnout and depression collectively contribute to sleep quality.

Methods: Professional firefighters in Northern Iran completed a survey comprised of demographic information, the Pittsburgh Sleep Quality Index, HSE's Stress Indicator Tool, the Posttraumatic Stress Disorder Checklist, Maslach's Burnout Inventory, and the Beck Depression Inventory during a work rest break. Data were analysed using structural equation modelling.

Results: Mean age of the 2339 firefighters who completed the survey was 32.30 (5.74) years. Most experienced poor sleep quality, scoring above the established cut-off of 5. Levels of work-related stress, post-traumatic stress, burnout and depression were high. Fit indices of the final theoretical model were all adequate: the obtained and adjusted goodness-of-fit indices were 0.925 and 0.917 respectively. Comparative, and incremental fit indices were 0.946 and 0.948 respectively. Root mean squared error of approximation was 0.061. Post-traumatic stress was directly and indirectly related to sleep quality through eight paths, modulated by burnout variables and depression. Work-related stress was negatively related to sleep quality through four paths modulated, by burnout variables and depression.

Conclusions: The findings illustrate the complex relationships of work-related stress and post-traumatic stress and sleep quality. High levels of poor sleep quality in this occupation emphasise the need to develop targeted and sustainable interventions to manage occupational stressors, burnout and depression to improve sleep quality in firefighters.