This was a cross-sectional survey conducted via an anonymous, self-administered online questionnaire. Data were collected via a structured questionnaire distributed through an online platform—Wenjuanxing (Questionnaire Star), a widely used professional online survey tool in China with functions of data encryption and real-time data management to ensure data security and accuracy. The questionnaire was designed on the basis of validated scales in previous literature and adjusted for the nursing context and pretested for content validity and reliability with a pilot test involving 20 nurses, resulting in a Cronbach’s α coefficient of 0.82–0.93 for the main scales, indicating good internal consistency.

Data collection was conducted from June 2025 to August 2025. The survey was distributed through online nursing workgroups across mainland China. These workgroups consisted of nurses from various healthcare institutions, including tertiary hospitals, secondary hospitals, and primary care facilities, covering different clinical departments (e.g., internal medicine, surgery, emergency, and intensive care units). The workgroups were accessed through collaboration with local nursing associations, hospital nursing departments, and head nurses, who disseminated the questionnaire link via WeChat (a dominant social media platform in China) workgroups to eligible nurses. The participants completed the questionnaire voluntarily online, with no time or location restrictions other than internet access.

Participants were eligible if they met the following inclusion criteria: (1) registered nurses with a valid nursing license; (2) currently engaged in clinical nursing work (excluding administrative or retired nurses); (3) able to understand and complete the online questionnaire independently (without cognitive or language barriers); and (4) voluntarily agreed to participate in the study.

The exclusion criteria were as follows: (1) nursing students or intern nurses without formal employment; (2) nurses on long-term leave (≥ 3 months) during the survey period; and (3) incomplete questionnaire responses (defined as missing > 10% of key items, on the basis of predefined criteria).

A convenience sampling method was used to recruit 1173 participants, and 1133 individuals were ultimately included in the analysis. The questionnaire link, along with a brief introduction of the study (purpose, confidentiality, and estimated completion time), was distributed through WeChat workgroups of nurses. These workgroups were identified through professional networks, local nursing associations, and hospital nursing management teams to ensure coverage of diverse nursing settings (e.g., urban vs. rural hospitals, general vs. specialized hospitals). The participants were informed of the study’s voluntary nature, anonymity (no personal identifiers were collected, such as name or employee ID), and the right to withdraw at any time without consequences.

The Maslach Burnout Inventory (MBI) was used to assess occupational burnout, developed by Maslach et al^[] and revised by Zhang et al.^[]. The MBI comprises 22 items rated on a Likert scale from 0 (never) to 6 (every day), covering three dimensions: emotional exhaustion, depersonalization, and personal accomplishment. Higher scores indicate greater severity of burnout. Occupational burnout was assessed using the Maslach Burnout Inventory-Human Services Survey (MBI-HSS). Official permission to use the MBI was obtained from Mind Garden, Inc. (www.mindgarden.com). The Chinese version of the MBI-HSS^[], which has been validated in previous studies^[], was used in this study. In this study, burnout was treated as a continuous variable. The scale demonstrated good reliability and validity in this study (Cronbach’s α = 0.91).

The PSS was first developed by Cohen et al. (1983) as 14 items^[]. The Perceived Stress Scale is a self-report instrument designed to assess perceived psychological stress over the preceding 30 days. The respondents rated each item on a five-point Likert-type scale ranging from 0 (never) to 4 (very often). The item scores are summed to produce a total score between 0 and 40, with higher scores indicating greater perceived stress. The PSS has good reliability and validity among Chinese nurses^[],[]. In this study, perceived stress was treated as a continuous variable. The scale demonstrated good reliability and validity in this study (Cronbach’s α = 0.83).

Insomnia screening was conducted via the Insomnia Severity Index (ISI)^[], a seven-item instrument that assesses the severity and frequency of insomnia symptoms and their impact on daily functioning. The total scores range from 0–28, with higher scores indicating more severe insomnia.The Chinese version of the ISI, which has been validated in previous studies^[],[]. In this study, insomnia was treated as a continuous variable. The scale demonstrated good reliability and validity in this study (Cronbach’s α = 0.82).

This study used the generalized anxiety disorder-2 (GAD-2) scale to screen for generalized anxiety disorder^[]. Generalized anxiety disorder (GAD-7) is the most prevalent anxiety disorder encountered in primary care^[].GAD-2 can be seen as an efficient and streamlined screening tool for GAD-7^[]. It comprises two items: “Over the past 2 weeks, how often have you felt nervous, anxious, or on edge?” and “Over the past 2 weeks, how often have you been unable to stop or control worrying?”

Depressive symptoms were screened using the 2-item Patient Health Questionnaire (PHQ-2)^[], a valid and reliable brief tool derived from the full PHQ-9^[]. A score of 3 or higher was used as the cut-off point to indicate potential clinical depression.PHQ-2 comprises two items: “Over the past 2 weeks, how often have you been bothered by little interest or pleasure in doing things?” and “Over the past 2 weeks, how often have you been bothered by feeling down, depressed, or hopeless?”. The PHQ-2 has demonstrated good reliability and validity in China, and its psychometric properties have been well-validated across various meidical populations^[].

The measures of depressive and anxiety disorders were combined into a single variable termed psychological distress. This variable comprises four items, each rated on a 4‑point scale from 0 (never) to 3 (almost every day). Total scores range from 0 to 12, with higher scores indicating greater psychological distress. In this study, psychological distress was treated as a continuous variable. The scale demonstrated good reliability and validity in this study (Cronbach’s α = 0.93).

Resilience was evaluated via the revised Chinese version of the 10‑item Connor–Davidson Resilience Scale (CD‑RISC‑10)^[]. The scale contains 10 items rated on a 5‑point Likert scale (0–4, from “never” to “always”). Total scores are obtained by summing item responses, with higher scores indicating greater resilience. This scale is widely used in China^[] and has good reliability and validity^[]. In this study, resilience was treated as a continuous variable and Cronbach’s α = 0.96.

First, Pearson correlation analysis was conducted to examine the associations among the study variables. Second, a moderated chain mediation model was tested via the PROCESS macro (version 4.2) via SPSS (version 23.0) software. The chain mediation pathways were estimated by entering the independent variable and the mediators sequentially into the regression models, and moderation was tested by including the appropriate interaction terms between the proposed moderator and the focal predictors on the paths of interest. Conditional indirect effects (i.e., indirect effects at different levels of the moderator) were estimated with a bias‑corrected bootstrap procedure based on 5,000 resamples. Indirect effects were considered statistically significant when the 95% bias‑corrected bootstrap confidence interval did not include zero. Third, when a significant moderator×predicator interaction was observed, simple slopes were probed at the mean and ± 1 SD of the moderator. All the models reported unstandardized coefficients, standard errors, and 95% confidence intervals. Covariates were included in all relevant regression equations. We conducted a sensitivity analysis to compare the results across different departments. The missing data were directly deleted (with a missing proportion of less than 3% and random missing data). The direction and significance of the key findings of both methods remain consistent, which enhances the robustness of our conclusions (Appendix 1).

Harman’s single‑factor test was conducted to assess common method bias. Four factors had eigenvalues greater than 1, and the initial factor accounted for 21.54% of the total variation, which is below the conventional 40% threshold, indicating that this study was not affected by any significant degree of common method bias^[].

A total of 1,133 nurses were included in the study. The majority of nurses were female, with a mean age of 34 years; most participants held an undergraduate degree, were married, were employed on a contractual basis, reported an annual income below RMB 80,000, and worked 36–45 hours per week (Table 1).

Correlation analyses were conducted for perceived stress, insomnia, psychological distress, burnout and resilience. As shown in Table 2, perceived stress was significantly and positively correlated with insomnia, psychological distress, and burnout. Insomnia was significantly and positively correlated with psychological distress and burnout, and psychological distress was significantly and positively correlated with burnout (p < 0.01).

After controlling for gender, age, department, professional title, income, and working hours, we tested a moderated chain mediation model (Table 3). Perceived stress significantly and positively predicted occupational burnout (β = 0.49, p < 0.001) and significantly and positively predicted both insomnia (β = 0.40, p < 0.001) and psychological distress (β = 0.31, p < 0.001). Insomnia significantly and positively predicted psychological distress (β = 0.16, p < 0.001). Psychological distress significantly and positively predicted occupational burnout (β = 2.48, p < 0.001). Moreover, insomnia and psychological distress sequentially mediated the association between perceived stress and occupational burnout. These findings demonstrate a significant chain mediating effect of insomnia and psychological distress on the relationship between perceived stress and burnout.

After resilience was incorporated into the model analysis, the interaction effect of resilience and perceived stress on insomnia was found to be significant (β= -0.01, p < 0.01). The interaction effect of resilience and perceived stress on psychological distress was found to be significant (β= -0.00, p < 0.001). These findings indicate that resilience moderates the relationship between perceived stress and insomnia and the relationship between perceived stress and psychological distress (Table 3). The results of the moderated chain mediation pathway are illustrated in Fig. 1.

Furthermore, to reveal the moderating effect of resilience in the chain mediation path, we divided resilience into two groups (high and low) on the basis of the mean score plus or minus one standard deviation. The effects of perceived stress on insomnia and of perceived stress on psychological distress under different levels of resilience were calculated. At one standard deviation below the mean of resilience (M-1SD), the conditional indirect effect of perceived stress on burnout via psychological distress was significant (β = 0.63, 95% CI: 0.40–0.90). At one standard deviation above the mean of resilience (M + 1SD), the conditional indirect effect remained significant (β = 0.45, 95% CI: 0.29–0.65), and the indirect effect under high resilience was smaller than that under low resilience. These findings indicate a significant moderated mediation in which resilience moderates the indirect effect of perceived stress on occupational burnout through psychological distress. At one standard deviation below the mean of resilience (M-1SD), the chain mediation effect of perceived stress on burnout via insomnia and psychological distress was significant (β = 0.12, 95% CI: 0.06–0.19). At one standard deviation above the mean of resilience (M + 1SD), the chain mediation effect remained significant (β = 0.06, 95% CI: 0.03–0.10). The total effect in the high-resilience group was significantly lower than that in the low-resilience group. These results indicate a significant moderated chain mediation effect: resilience moderates the indirect pathway from perceived stress to burnout through insomnia and emotional distress (Table 4, Fig. 2 and Fig. 3).

After controlling for age, sex, department, professional title, income and working hours, the regression coefficient was obtained.

After controlling for age, sex, department, professional title, income and working hours, the regression coefficient was obtained

This study explored the mechanism underlying occupational stress and burnout in Chinese nurses, with a focus on the buffering role of psychological resilience and the chained mediating effects of insomnia and emotional distress. Our key findings are threefold. First, occupational stress is positively associated with burnout, which is consistent with decades of research on nurse burnout. Second, insomnia and emotional distress sequentially mediated the pathway from occupational stress to burnout, forming a "stress→insomnia→emotional distress→burnout" chained mediation model. Third, psychological resilience buffers this pathway such that greater resilience weakens the positive links between occupational stress and insomnia and between emotional distress and burnout and reduces the overall indirect effect of stress on burnout through chained mediators. These results collectively highlight the critical role of both intermediate processes (insomnia, emotional distress) and a protective factor (psychological resilience) in shaping nurses’ burnout trajectories.

The direct association between occupational stress and burnout aligns with established frameworks such as the job demands-resources (JD-R) model, which posits that unmanageable job demands (e.g., heavy workload, emotional labor in nursing) deplete personal resources, leading to burnout^[]. Our findings extend this research by identifying a chained mediation pathway and clarifying how stress operates through sequential psychological and physiological strain. Insomnia, as an early mediator, resonates with prior research showing that occupational stress disrupts sleep homeostasis, particularly in nurses, due to irregular shifts, work overload, and emotional exhaustion^[],[]. By disrupting natural circadian rhythms, these mechanisms degrade sleep quality and quantity, thereby inducing prolonged sleep impairment. For example, Nguyen & Liu (2022) ^[]reported that nurses with high perceived stress were 1.27 times (95% CI: 1.19–1.36) more likely to report sleep disturbance, which in turn predicted increased burnout risk. Our study advances this by demonstrating that insomnia does not act in isolation but propagates stress through emotional distress—a finding that is consistent with the transdiagnostic model of psychopathology, which emphasizes that sleep disturbances exacerbate negative affect and emotional dysregulation^[]. A cross-sectional survey of Chinese nurses revealed that higher scores on the global PSQI (β = 0.235, p < 0.01) and its components of subjective sleep quality (β = 0.101, p < 0.05), sleep disturbances (β = 0.119, p < 0.01), and daytime dysfunction (β = 0.142, p < 0.01) were all significant positive predictors of psychological distress^[]. Psychological distress (e.g., anxiety, depression) as the second mediator aligns with evidence that chronic stress-induced emotional arousal depletes coping resources, fostering burnout. Nurses suffering from burnout commonly demonstrate symptoms such as anxiety, depression, and emotional fatigue. This symptom cluster adversely affects their professional performance and the quality of patient interactions^[]. A reciprocal interplay can ensue, resulting in a vicious cycle: psychological distress aggravates burnout, which in turn heightens distress, consequently contributing to continual degradation of the healthcare workforce. Abd El-Fatah et al. (2025) reported that the statistically significant correlation between burnout and psychological distress (r = 0.59, p < 0.001) indicates that higher levels of burnout are associated with increased psychological distress^[]. Previous research aligns with our study.

A number of studies have shown that greater resilience protects nurses from emotional exhaustion and contributes to their personal accomplishment^[],[]. Our finding that psychological resilience buffers the stress‒burnout pathway supports the conservation of resources (COR) theory, which argues that personal resources (e.g., resilience) mitigate resource loss under stress^[]. Specifically, resilience weakened the link between occupational stress and insomnia, suggesting that resilient nurses may employ adaptive coping strategies (e.g., cognitive reappraisal, problem solving) to reduce stress-related hyperarousal, thereby preserving sleep quality. This aligns with studies showing that resilience predicts better sleep outcomes in high occupational stress nurses in China^{[] []}. Mediation analysis revealed that resilience operates protectively as a negative mediator in the relationship between stress and psychological distress, indicating that resilient nurses may better regulate negative emotions, preventing them from escalating into chronic burnout. This finding complements prior work by Lorente et al.^[], who reported that emotion-focused strategies are negatively related to nurses' psychological distress directly and indirectly through resilience, but our study specifies where this buffering occurs—strengthening the mechanistic understanding of resilience as a "protective filter" across multiple stages of stress transmission. Overall, psychological resilience, as an important personal resource, can significantly reduce the negative impact of stress (X) on insomnia (M1) and psychological distress (M2). It helps nurses maintain better sleep quality and emotional stability during adversity, thereby preventing stress from developing along the path of "insomnia→emotional deterioration" and protecting mental health.

The implications of this research can be divided into two parts: theoretical and practical.

Theoretical Implications: Our research provides an integrated framework that links multiple fields, such as occupational stress, sleep medicine, and affective neuroscience, to more comprehensively reveal the mechanisms underlying nurse burnout. The theory of resource conservation has been verified and expanded, indicating that psychological resilience is a critical personal resource that can protect other resources, such as sleep quality and emotional stability, from being consumed by stress. Practical Implications: 1) Proactive intervention measures: hospital managers should not only focus on nurses who have already experienced fatigue but also intervene early. Regular screening of nurses' sleep quality and emotional state can serve as an early warning system. 2) Building resilience training programs: Evidence-based psychological resilience training programs (such as mindfulness-based stress reduction therapy and cognitive‒behavioral therapy skills training) must be designed and implemented to increase nurses' ability to cope with stress. 3) Improving the organizational environment: fundamentally reducing sources of occupational stress (such as reasonable scheduling, providing supportive leadership, and establishing a culture of fairness) remains a top priority. Resilience training cannot be an excuse for organizations to shirk responsibility.

The main innovations and contributions of this study are as follows:

We must acknowledge the shortcomings of the research and provide recommendations for future research: 1) Cross-sectional design: cannot determine an absolute causal relationship. Although the model is theoretically reasonable, reverse causality or other explanations may exist. Future directions: Longitudinal or diary studies should be conducted to track the changes in these variables over time. 2) Self-report measures: All the data come from questionnaires, and there may be recall bias that affects credibility. Future research can combine objective indicators such as actigraphy to measure sleep, physiological indicators (cortisol levels), or job performance evaluated by colleagues/supervisors. 3) Sample representativeness: The majority of the samples were from North China and tertiary hospitals, limiting the generalizability of the results. Our sample primarily included hospital-based nurses, and the results may not extend to community nurses or those in specialized settings (e.g., psychiatric nursing). Future directions: Multicenter studies should be conducted in different regions and levels of hospitals (such as community hospitals vs. tertiary hospitals) to verify the stability of the model. 4) Other unexplored variables: There may be other important mediating or moderating variables (such as social support, mindfulness, and job satisfaction). Future direction: We can build more complex models that incorporate these variables.

In conclusion, this study elucidates a potential mechanism—the insomnia-emotional distress pathway—through which occupational stress infiltrates the lives of nurses and culminates in burnout. More importantly, this study highlights the critical protective role of psychological resilience in disrupting this pathway at its origin. These findings underscore the necessity of developing multifaceted interventions that not only mitigate workplace stressors but also increase nurses’ internal capacity to cope, ultimately safeguarding their well-being and the quality of care they provide.