The mediating role of self-regulatory fatigue on the relationship between insomnia and sleep-related worry among shift nurses: a cross-sectional study

Shift work frequently disrupts circadian rhythms in nurses, posing threats not only to their physical and mental health but also potentially impacting the quality of care and patient safety. Nurses are a high-risk group for sleep-related worry, yet the intrinsic mechanisms linking insomnia, self-regulatory fatigue, and sleep-related worry among shift nurses remain unclear. This study aimed to explore the mediating role of self-regulatory fatigue in the relationship between insomnia and sleep-related worry. This cross-sectional study employed a convenience sampling method to survey shift nurses from a tertiary Grade A general hospital in Zunyi City between February and April 2025. Data were collected using a general information questionnaire, the Athens Insomnia Scale (AIS), the Self-Regulatory Fatigue Scale (SRF-S), and the Anxiety and Preoccupation about Sleep Questionnaire (APSQ). Univariate analysis, Spearman correlation analysis, and hierarchical regression analysis were conducted to investigate factors influencing sleep-related worry. Structural equation modeling was used to test the mediating effect of self-regulatory fatigue. The final sample comprised 988 participants, predominantly female (92.21%), aged 31–40 years (53.14%), and married (74.09%). Spearman correlation analysis revealed significant positive correlations between insomnia and self-regulatory fatigue (r = 0.557), between insomnia and sleep-related worry (r = 0.679), and between self-regulatory fatigue and sleep-related worry (r = 0.565) (all P < 0.01). Structural equation modeling indicated that self-regulatory fatigue played a partial mediating role in the relationship between insomnia and sleep-related worry, with a mediation effect value of 0.226 (95% CI: 0.177, 0.277), accounting for 32.56% of the total effect. Shift nurses experience a relatively high level of sleep-related worry. Self-regulatory fatigue partially mediates the relationship between insomnia and sleep-related worry in this population. This suggests that nursing managers should adopt comprehensive measures, focusing on both improving nurses’ insomnia and reducing their levels of self-regulatory fatigue to effectively alleviate sleep-related worry.