Work-Related Accumulated Fatigue among Doctors in Tertiary Hospitals: A Cross-Sectional Survey in Six Provinces of China

Objectives: “Karoshi” (death due to overwork) of doctors occurred frequently and attracted increasing attention in recent years in China. This study aimed to determine the prevalence of work-related accumulated fatigue of doctors and its associated factors in tertiary hospitals of China. Methods: A cross-sectional questionnaire survey was conducted on 1729 full-time doctors employed by 24 tertiary hospitals across eastern developed, central developing, and western underdeveloped regions of China. Accumulated fatigue was categorized into four levels using the “Self-diagnosis Checklist for Assessment of Workers’ Accumulated Fatigue” rated on a scale matrix considering both overwork and fatigue symptoms. Ordinal logistic regression analyses were performed to identify factors associated with work-related accumulated fatigue. Results: About 78.8% of respondents reported a “high level” of work-related accumulated fatigue, including 42.0% at a “very high” level. Male doctors and those aged between 30 and 45 years and who had a professional title were found to have higher levels of accumulative fatigue than others. Low salary and poor working conditions (in the western region) were also significantly associated with high levels of work-related accumulated fatigue (p < 0.05). Conclusion: High levels of work-related accumulated fatigue are prevalent in doctors working in tertiary hospitals in China. Male doctors establishing their early- and mid-careers are the high-risk group. Poor working conditions are associated with work-related accumulated fatigue.


Introduction
Overwork is often associated with high levels of accumulated fatigue, which not only affects the health and wellbeing of doctors but also jeopardizes the work performance of doctors, resulting in increased patient safety risks [1,2]. Empirical evidence shows that accumulated fatigue can accelerate thrombotic reactions [3] and even lead to sudden cardiac arrest [4]. The medical and health service industry is particularly prone to work-related accumulated fatigue due to its special nature, such as long and irregular working hours and a shortage of breaks and sleep [5][6][7]. Work-related accumulated fatigue was proved to be associated with burn-out of doctors [8][9][10]. In Japan and Korea, cerebrovascular and cardiovascular diseases (CVDs) associated with overwork have been recognized by the government for work compensation [11,12].
Overwork has been reported as a silent killer of doctors in China [13,14]. The sudden death of three doctors from two prestigious tertiary hospitals in Beijing over a two-week period in October 2014 attracted sensational media attention [15]. Karoshi, a term that originated in Japan describing death

Participants
A multi-stage cluster sampling strategy was employed to select questionnaire respondents. Overall, the study participants were not selected randomly. However, random sampling was adopted in selecting the participating hospitals. The 31 provinces (or equivalent) in mainland China were divided into three economic zones: eastern developed (high income and social development), central developing, and western underdeveloped. At the first stage, two provinces with a middle range of socioeconomic status within each zone (Table 1) were selected: Shandong and Hebei for the east; Hubei and Henan for the central; and Qinghai and Guizhou for the west. The second stage involved a selection of two municipalities in each province: one capital and another non-capital, except for Qinghai, where tertiary hospitals are highly concentrated in the capital city. At the third stage, two tertiary hospitals in each municipality (four in the capital city of Qinghai) were identified randomly. Finally, about 80 questionnaires were dispatched to each selected hospital (a pilot survey in Hubei province indicated that a sample size of 80 medical doctors was achievable in a tertiary hospital and met the statistical power requirement for data analyses). Full-time doctors employed by these hospitals from all of the units were invited to complete the questionnaire anonymously on a voluntary basis. The questionnaire contained an information sheet explaining the purpose and the protocol of the research. Return of the completed questionnaire was deemed informed consent. Data were collected from January to November 2018. A team comprising several trained research students led by one of the principal investigators visited the participating hospitals, approached the doctors on the day of their visits, invited them to complete the questionnaire independently, and collected the completed questionnaires on the sites. None of the team members had any relationship with the respondents. This resulted in a total of 1729 completed questionnaires, accounting for 90.05% of dispatched questionnaires. The sample size was large enough to enable inclusions of over 30 independent variables in the statistical modeling [34].

Measurements
The "Self-diagnosis Checklist for Assessment of Workers' Accumulated Fatigue" was published by the Ministry of Health, Labor and Welfare of Japan, which has been validated in a range of healthcare settings in Japan, China, and some other countries [35][36][37]. The translated Chinese version demonstrated good reliability and construct and discriminatory validity in various populations in China [37,38]. In this study, high internal consistence of this instrument was evident, as indicated by the Cronbach's alpha: 0.936 for "fatigue symptoms" and 0.853 for "work burdens".
The "Self-diagnosis Checklist for Assessment of Workers' Accumulated Fatigue" uses a scale matrix measuring work-related accumulated fatigue. Respondents were asked to rate their feelings over the past month. Fatigue symptoms (e.g., irritable moods, anxiety, restlessness, poor concentration, etc.) were rated with 13 items on a three-point scale: 0 (rarely), 1 (sometimes), and 3 (often). The symptom scores were then summed up and classified into four levels: I (0-4); II (5-10), III (11)(12)(13)(14)(15)(16)(17)(18)(19)(20), IV (>20). This was then mapped into the work status scale comprising four levels of work burdens. The work status scale contained 7 items measuring overwork status as well as physical and mental burdens of both regular (e.g., day and night duties) and irregular (e.g., sudden job and business trip) work arrangements on a two-or three-point scale, with a higher score indicating inadequate or heavier burdens. This resulted in a summed score ranging from 0 to 15, which was categorized into four levels of work burdens: A (0); B (1-2); C (3)(4)(5); and D (≥6). The combination of the two scales generated a score algorithm reflecting the degree of work-related accumulated fatigue ( Table 2). It is generally believed that an adequate work burden should fall into the cells labeled 0 and 1 [37]. Independent variables associated with work-related accumulated fatigue were selected in reference to previous studies [5,13,39]. It has been widely accepted that work-related accumulated fatigue needs to be addressed through a systems approach that includes adequate work conditions and job assignments and a balance between work and life [6]. In line with the literature, the independent variables tested in this study covered the demographic characteristics (gender and age) of the respondents, their professional standing and job requirements (measured by qualification, professional title, and years of working experience), work conditions (monthly salary and location of hospitals), and family commitment (marital status and children). Significant regional disparities exist in China in terms of hospital infrastructure and staff welfare. The less developed regions (such as western China) usually have relatively low hospital resources despite worse population health status. Those hospitals are also poorly resourced and usually are not able to afford the same level of welfare support to their staff members as what is given to those in the more developed regions (such as eastern China) [40].

Statistical Analysis
Data were inputted into the EpiData Info 3.1 database and analyzed using the SPSS 19.0. Work-related accumulated fatigue was ranked into four levels in line with the scale matrix algorithm: low (0-1), a little high (2-3), high (4)(5), and very high (6-7). Pearson Chi-square tests were performed to identify independent variables that were associated with work-related accumulated fatigue. Those with a statistical significance (p < 0.05) were entered into an ordinal logistic regression model to test their statistical significance (p < 0.05) in association with work-related accumulated fatigue after controlling for variations in other independent variables.
We performed two regression analyses using two different measures for the dependent variable. The major findings reported in the manuscript used the scale matrix score as a dependent variable, which considered both "fatigue symptoms" and "work burdens". As a result, workloads and work scheduling were excluded from the modelling simply because they overlapped with "work burden" measurements in the scale matrix. In the second regression analysis (reported in the Appendix A), we singled out "fatigue symptoms" as the dependent variable, which allowed us to include workloads and work scheduling in the modeling.

Characteristics of Respondents
About 53.7% of respondents were men and 46.3% were women. The majority (53.7%) of respondents were aged between 30 and 45 years. Most (74.4%) were married at the time of the survey. More than half (51.0%) of the respondents had only one child, compared with 34.9% having no child and 14.1% having two or more children. A very small percentage (1.9%) of respondents did not have a medical degree due to disruptions in their medical education during the Cultural Revolution (1966)(1967)(1968)(1969)(1970)(1971)(1972)(1973)(1974)(1975)(1976)). On average, respondents from the eastern hospitals had higher qualifications (χ 2 = 309.253, p < 0.001) and earned a higher income (χ 2 = 40.770, p < 0.001) than their central and western colleagues (Table 3).

Work-Related Accumulated Fatigue and Associated Factors
About 21.2% of respondents reported a low level of work-related accumulated fatigue, compared with 23.4% reporting a high level and 42.0% reporting a very high level of accumulated fatigue. Men (χ 2 = 10.823, p = 0.013) and those who were 30-45 years of age (χ 2 = 26.410, p < 0.001), held a professional title (χ 2 = 35.184, p < 0.001), earned a lower salary (χ 2 = 28.309, p < 0.001), and worked in the central/western regions (χ 2 = 31.975, p < 0.001) were more likely to report higher levels of work-related accumulated fatigue (Table 4). The two regression models produced similar results, although age and gender became insignificant in predicting the level of fatigue symptoms without being linked to work burdens (Appendix A Table A1 and Appendix A Table A2). For simplicity of reporting, we only present the results of the ordinal logistic regression model on the "fatigue/work burden" scale matrix scores. The ordinal logistic regression model confirmed that gender, age, professional title, salary income, and hospital location were significantly associated with work-related accumulated fatigue after controlling for variations in other independent variables. The odds of male doctors having a higher level of work-related accumulated fatigue were 1.379 (p < 0.001) times those of female doctors. Those aged between 30 and 45 years were 1.487 times more likely to report a higher level of work-related accumulated fatigue than their older counterparts (p = 0.003). Higher levels of work-related accumulated fatigue were also confirmed in those who earned less income (p < 0.05), worked in the western region (p < 0.01), and had a professional title (p < 0.01) ( Table 5).

Discussion
Our study demonstrated that 23.4% and 42.0% of doctors working in tertiary hospitals in mainland China experienced high and very high levels of accumulated fatigue, respectively. Such a prevalence and degree of work-related fatigue is quite high compared with the findings of studies conducted in other sectors, such as enterprise workers and lawyers [37,41,42]. However, it is consistent with the findings of several other studies on hospital medical workers in mainland China, although only fatigue symptoms were measured in those studies [43,44]. Taiwan has a different health system compared with mainland China, and about 31% of hospital workers in Taiwan reported work-related fatigue symptoms [45]. Internationally, the prevalence of work-related fatigue ranged from 7% to 45% [46].
The health industry is notorious for its high stress nature, often resulting in a prevalence of fatigue at the higher end of the spectrum. Fatigue impairs the physical and the cognitive functioning of health workers, which has been recognized as a safety risk to the workers themselves and the patients they care for [27,29,30,47]. Occupational injuries (such as musculoskeletal disorders and needlestick injury) and emotional distress and exhaustion, burnout, depression, as well as occupational stress-related cardiovascular diseases were often reported as being associated with overwork and fatigue [27,[47][48][49][50]. The negative impact of fatigue on work performance has also been well documented in a wide range of health care arenas involving both physicians and nurses [32,51]. A study concluded that an average of longer than 40 hours weekly workloads in nurses, including voluntary paid overwork, is associated with 14% to 28% higher reported adverse events such as medication error, patient falls, and nosocomial infections [51].
The excessive workloads of medical doctors have shown little, if any, sign of relief in mainland China. Despite great efforts from the government to encourage more patients to seek medical attention from primary care facilities, consumers enjoy the freedom to choose their preferred providers [24]. There is a lack of consumer trust in primary care in general [13]. Hospitals, as consumer preferred providers, are still incentivized to service more patients for financial gains under the limited government budget support and fee-for-service payment arrangements [52]. This generates a strong incentive for physicians to seek profits in medical services [53]. All these factors contribute to the high patient load on hospitals, especially tertiary hospitals. At present, there is no legislation in mainland China restricting the workloads of health workers.
Work environment is an important factor associated with work-related accumulative fatigue in medical doctors. This study proved that low salary levels and a western location are independent predictors of higher levels of work-related accumulative fatigue after adjustments for variations in other factors. Overall, the total health expenditure in China is low, accounting for about 6% of gross domestic product (GDP) (compared with over 10% in most developed countries) [54]. This led to low salaries and poor work conditions in many health facilities. Because health financing responsibilities are devolved to local governments, hospital work conditions in the underdeveloped western region are usually poorer than their richer counterparts in the eastern region [55]. By the end of 2017, the eastern urban areas had 4.3 doctors per 1000 population, compared with 3.7 in the central and 3.6 in the western areas in China [54]. Medical doctors in the western region have to work longer with a lower salary but enjoy fewer opportunities for career advancement [50]. The sharp contrast between the eastern and the western regions may add some additional psychological loads on medical workers in the western region, fueling work-related fatigue.
Studies about the role of home duties on work-related fatigue generated mixed results [28]. While some claimed that household work and a higher level of family commitment such as care for children can exacerbate fatigue [5,30], others argued that family support can aid the recovery of work-related fatigue [56]. In this study, we did not find evidence to support an association between work-life conflicts and work-related fatigue. Neither marital status nor number of children were found to be significant predictors of accumulated fatigue. However, male doctors and those aged between 30 and 45 years were found to have higher levels of work-related accumulative fatigue than others. This age group represents those who are establishing their early-and mid-careers. A study of 46 overwork-associated death cases in medical doctors in China revealed that most of the victims were male (43/46) and in the age bracket of 30-39 years [13].
A systematic approach is needed to address work-related accumulative fatigue issues in medical doctors. Interventions should not be restricted to those targeting individual work scheduling and coping strategies. Adequate job design, staff welfare, and work conditions are equally-if not more-important. Shortening work hours is the first step to reducing work-related fatigue. However, this has never been an easy task in healthcare, not only because there is a continuous shortage of workforce, but also because long working hours and long shifts are often considered necessary for health workers to be exposed to a sufficiently broad spectrum of cases for skill and competency gains [27,32]. There is a lack of empirical evidence to support scheduling interventions [27]. The fatigue-related risk in healthcare has to be addressed through better organizational management and organizational culture [32]. Unfortunately, modern medical and organizational management is founded on the culture of "commitment and diligence", often at the cost of "stress and fatigue" of employees [27]. If we are serious about "putting patient safety at the center of care", exhaustion of health workers should no longer be seen as a sign of dedication [32]. Future studies should explore the potential impacts of consumer and management pressures on the development of work-related accumulative fatigue.

Limitations
There are several limitations in this study. The study adopted a cross-sectional design. No causal relationships should be assumed. Participants of the study were selected from tertiary hospitals. The findings should not be extrapolated to primary and secondary hospitals. We used a scale matrix measuring work-related accumulated fatigue. Although it does not indicate a direct causal relationship between work burdens and fatigue, a significant association between work burdens and accumulated fatigue is evident. The coexistence of overwork and fatigue deserves serious concern.

Conclusions
High levels of work-related accumulated fatigue are evident in medical doctors working in tertiary hospitals in mainland China, which are associated with gender, age, and work conditions. Male doctors as well as those who are in the age of 30-45 years, have a professional title, and earn a low salary are more likely to experience higher levels of work-related accumulated fatigue. There also exist regional disparities. Medical doctors working in the underdeveloped western region are more likely to experience work-related accumulated fatigue than their richer eastern and central counterparts. A systematic approach is needed to address the inequalities of work-related accumulated fatigue in medical doctors within and across organizations.
Author Contributions: C.T. coordinated data collection, performed statistical analyses, and wrote the first draft. C.L. led the articulation of research questions, interpretation of results, and writing of the manuscript. P.F., Y.X. and R.M. participated in data collection and statistical analyses. All of the authors contributed to the conceptualization of the project and writing of the manuscript.
Funding: This study was supported by the National Natural Science Foundation of China (No. 71603077).

Acknowledgments:
We thank all the medical doctors who participated in the study and the research assistants who were involved in data collection.

Conflicts of Interest:
The authors declare no conflict of interest.