In this study, the relationship between working hours, occupational stress, and cumulative fatigue among 1,327 primary health care professionals was examined. 

The research aimed to fill a gap in the existing literature by investigating the mediating role of occupational stress in the association between working hours and cumulative fatigue. Utilizing the Core Occupational Stress Scale and the Workers' Fatigue Accumulation Self-Diagnosis Scale, the study employed hierarchical regression analysis and Bootstrap tests to explore the mediating effect of occupational stress.

The findings indicated a significant positive correlation between working hours and cumulative fatigue, which was partially mediated by occupational stress (p < 0.01). The mediating effect of occupational stress was measured at 0.078 (95% CI: 0.043–0.115, p < 0.01), constituting 28.3% of the mediating effect. The study's outcomes underscore the intricate interplay between working hours, occupational stress, and cumulative fatigue, suggesting that the impact of extended working hours on cumulative fatigue is influenced by the presence of occupational stress. Consequently, addressing occupational stress could potentially alleviate the symptoms of cumulative fatigue stemming from prolonged working hours

Working Hours and Cumulative Fatigue:

The average daily working hours of primary health care professionals were approximately 8.5 hours, with around 33.5% engaging in overtime work. The study observed a positive correlation between working hours and cumulative fatigue symptoms, indicating that longer working hours were associated with more severe cumulative fatigue. Notably, 57.5% of participants showed symptoms of cumulative fatigue.

Occupational Stress and its Impact:

Around 27.5% of primary health care professionals experienced occupational stress. Factors such as lower monthly income, being in the role of a doctor, and having shift or night shift duties were associated with higher levels of occupational stress. The study found a significant mediating role of occupational stress between working hours and cumulative fatigue, with occupational stress partially mediating the relationship. The mediating effect percentage was calculated at 28.3%.

Implications and Recommendations:

The research underscores the need for managing occupational stress and cumulative fatigue among primary health care professionals. Strategies to reduce cumulative fatigue symptoms involve limiting continuous working hours, ensuring reasonable shift schedules, and incorporating rest periods. Managers can consider facilitating short breaks during work hours and promoting physical exercise to improve overall well-being. Furthermore, addressing the balance between effort and reward through effective performance appraisal and salary distribution systems is recommended to alleviate occupational stress. Mindfulness meditation therapy and psychotherapy services could be integrated to enhance mental health. Overall, the study's findings emphasize the importance of promoting employee well-being through better management practices and strategies that address both working conditions and psychological stressors.

This study offers valuable personal insights into the complex interplay between working hours, occupational stress, and cumulative fatigue among primary health care professionals. One noteworthy insight pertains to the significant impact of extended working hours on cumulative fatigue. 

The study underscores that the demanding nature of the health care sector, often necessitating atypical and prolonged shifts, contributes to heightened fatigue levels. This finding resonates with real-world observations and highlights the need for interventions to mitigate the detrimental effects of long working hours.

The study effectively showcases how the relationship between working hours and fatigue is not merely linear but mediated by the intermediary factor of occupational stress. This insight underscores the importance of addressing not only the external factors of working hours but also the internal psychological experiences of professionals.

Additionally, the study's recommendations, such as mindfulness meditation and psychological counseling, offer a practical approach for addressing the complex issue of occupational stress and cumulative fatigue. This insight emphasizes the significance of holistic interventions that encompass both mental well-being and physical health. Moreover, the study's findings resonate with the larger discourse on work-related stress and fatigue, echoing concerns about the healthcare sector's demanding environment and its implications for professionals' overall well-being.