The Effect of Mental Workload on Nurses' Caring Behaviors: The Mediating Role of Secondary Traumatic Stress - A Cross-Sectional Correlational Study

Introduction: Nurses' caring behaviors play a critical role in communicating value, safety, and compassion to patients. Mental workload is a significant factor influencing these behaviors, with up to 93% of nurses reporting exposure to occupational stressors. Previous studies have shown that Secondary Traumatic Stress (STS), a condition resulting from indirect exposure to trauma, may serve as a mediator in the relationship between mental workload and caring behaviors. Therefore, this study aimed to examine the effect of mental workload on nurses' caring behaviors, with a particular focus on the mediating role of STS. Methodology: This cross-sectional correlational study employed Structural Equation Modeling (SEM) to analyze data collected from a total of 340 nurses working in teaching hospitals in Urmia, Northwest Iran. Data were collected using a demographic questionnaire, the NASA Task Load Index (NASA-TLX), the Secondary Traumatic Stress Scale (STSS), and the Caring Behaviors Inventory-24 (CBI-24). Statistical analysis was conducted using SPSS version 26, while SEM was conducted using SmartPLS 3 and Mplus 7.4 software packages. Results The majority of participants were female nurses (70.9%), with a mean age of 32.13 ± 6.30 years. SEM analysis showed that mental workload had a statistically significant positive effect on caring behaviors ( β  = 0.167), while STS had a significant negative effect ( β  = − 0.174). Furthermore, the indirect effect of mental workload on caring behaviors through STS was significant ( p  < 0.05), which confirmed the mediating role of STS ( TLI  > 0.9, CFI  > 0.9, RMSEA  < 0.08, SRMR  < 0.05). Conclusion Nurses are subject to high levels of both mental workload and STS, which have opposing effects on their caring behaviors. While mental workload may enhance certain aspects of care delivery, STS negatively impacts the quality of patient care. These findings further highlight the need for targeted interventions to manage STS and optimize mental workload to maintain and improve nursing care quality.