The major aims of the present study were to (1) address the prevalence of burnout syndrome among Chinese female nurses during the controlled COVID-19 period and (2) to explore its association with socio-demographic factors and job characteristics.

We used both multistage-stratified sampling and convenient sampling methods to collect data, a total of 100 cities and 1,740 nurses were randomly selected. The Chinese mainland consists of 32 provinces, which were divided into five regions according to geographical location: eastern, western, southern, northern, and central regions. In each region, 20 cities were randomly selected. An anonymous online survey was completed by a representative group of nurses across 100 cities in 31 provinces in China from September to October 2020 (a controlled COVID-19 period in China). In the second stage of sampling, the nurses who were originally selected were appointed to deliver the questionnaires to other nurses. The selected nurse was invited to click on a webpage link to access a self-administered questionnaire (https://www.wenjuan.com/). Subsequently, the web page link was sent by the deliverers to other nurses via mobile phones. The investigation purpose and significance of this study are shown on the front page of the self-administered questionnaire. The progress of the survey was monitored by the authors. Eventually, we checked the accuracy and completeness of the data and excluded the questionnaire. All data were checked for consistency by the two authors. A total of 1,740 nurses completed their questionnaires, resulting in 1,133 valid questionnaires, with an effective completion rate of 70.13%. The distribution of demographic variables (gender, age, and level of education) of the representative nurses is comparable to the general population of the Chinese registered nurses. The inclusion criteria were recognized as (1) being a registered nurse; (2) being currently enrolled in nursing; (3) gender is female; and (4) consent and voluntary participation in our study.

Statistical significance was considered as a two-tailed p-value < 0.05. All analyses were conducted using SPSS version 22.0 (IBM, BM SPSS Statistics for Windows). Demographic factors and job characteristics had been defined as independent variables, and total burnout had been defined as a dependent variable. Univariate and multivariate logistic regression analyses as the main statistical analysis methods were performed in the current study.

The age of the participants ranged from 20 to 55 years. Most (77.00%) participants had bachelor's degree and above. Of the 1,133 sampled nurses, 45.1% of them were unmarried, approximately 53.3% were married, and 1.6% were divorced or had loss of a spouse. Approximately 27.7% of them belonged to the primary professional category. Furthermore, a total of 529 nurses (46.7%) worked less than 6 years. Moreover, 74.8 and 32.2% of them experienced night-shifts work and worked 40 hours/week, respectively. Moreover, 27.19% had a monthly income within 2,001–5,000 RMB, as shown in Table 2.

The status of burnout of female nurses is shown in Table 3. Among 1,133 participating Chinese female nurses, a total of 782 reported experiencing varying degrees of burnout over the 2 weeks. The overall prevalence of all degrees of burnout was 60.20%, and the breakdown according to severity is as follows: 451 (39.8 %) mild, 163 (14.4%) moderate, and 68 (6.0%) severe burnout.

The analysis of the factors influencing burnout of Chinese female nurse is shown in Tables 4, 5. One of the classification variables was intentionally set as a “dummy” variable. Univariate logistic regression analysis of the development dataset included in the equation was as follows: (1) burnout as dependent variable (never = 0, exist = 1); (2) age of nurse (20–29 = 1, 30–39 = 2, 40–49 = 3, 50+ = 4); (3) marital status (unmarried = 1, married = 2, divorced or loss of a spouse = 3); (4) education level (technical secondary school= 1, college degree = 2, bachelors = 3, master degree, or above = 4); (5) parental status was divided into four categories (no child = 1, 0–5years = 2, 6–18 years = 3, 19, and above years = 4). (6) Professional title (primary: nurse = 1, primary: senior nurse = 2, medium: nurse-in-charge = 3, high: associate professor of nursing/professor of nursing = 4); (7) hospital level (tertiary hospitals = 1, non-tertiary hospitals = 2); and (8) hours/week (≤ 40 hours/week = 1, >40 hours/week = 2). (9) Job tenure (1–3 years = 1, 4–5 years = 2, 6–10 years = 3, 11–20 years = 4, 21, and above years = 5); (10) monthly salary income (RMB) (3,000 or below = 1, 3,001–5,000 = 2, 5,001–7,000 = 3, 7,001–9,000 = 4, 9,001 or above = 5); (11) night shifts (no = 1, yes = 2). According to our results, most female nurses (61.20%) exhibited varying degrees of burnout. Compared to female nurses aged 20–29 years old, female nurses aged 40–49 were not as prone to burnout. Age (Waldχ² = 14.562, P < 0.01, OR <1), parental status (Waldχ² = 17.688, P < 0.05, OR <1), professional title (Waldχ² = 12.748, P < 0.01, OR <1), working hours (Waldχ²= 4.466, P < 0.05, OR > 1), job tenure (Waldχ² = 28.826, P < 0.05, OR > 1), monthly salary income (RMB) (Waldχ² = 13.692, P < 0.05, OR > 1), and night shifts (Waldχ² = 5.341, P < 0.05, OR > 1) were the factors associated with burnout. These seven factors were then entered into the multivariate logistic regression model.

Further screening of the seven factors influencing burnout of female nurses is shown in Table 6. We analyzed the four factors selected by the univariate logistic regression analysis using multivariate factor logistic regression analysis. According to Table 4, the result of the significance test of the whole regression model is X² = 60.991 (P = 0.001, P < 0.01), while the result of the Hosmer-Lemeshow test is 2.132 (P = 0.459, P > 0.05); therefore, these regression models were optimal. As shown in Table 4, the results of the tests concerning the variables of job tenure (Waldχ² = 14.828, P < 0.05, OR <1), night shift (Waldχ² = 3.821, P < 0.01, OR > 1), and monthly salary income (RMB) (Waldχ² = 12.460, P < 0.01, OR <1) were significant, suggesting that these factors are the significant predictors of burnout among female nurses.

The burnout incidence in female nurses during the controlled COVID-19 period was 60.20%, with a breakdown in severity as follows: 451 (39.8 %) mild, 163 (14.4%) moderate, and 68 (6.0%) severe burnout, which was slightly lower than the initial stage of COVID-19 outbreak and slightly lower than that of predating COVID-19 ones (13). The current study on burnout in Chinese female nurses reported that 26.3% with high EE, 16.4% with high levels of DA, and 11.1% with low levels of personal achievement respectively among the participates. During the period of the COVID-19 outbreak, the anti-epidemic efforts of female nurses were positively evaluated by the public and media in China, which heartened the sense of achievement, career identity, and high-level self-recognition of female nurses, thus showing a decreased EE and less DA but more PA (38). Compared with Chinese doctors (21, 39), the overall prevalence of burnout of female nurses was lower involved less EE and less DA but more personal accomplishment. The study supports the view that burnout is still a common prevalence and worrying phenomenon in female nursing. In China, due to the increased contradictions between nursing care and expectation of patients (40), the exceeding work-family conflicts and work stress have been increasing especially in female nurses (41), resulting in a variety of potentially fatigued or hazardous circumstances for female nurses. Therefore, strategies, such as increasing job resources (42), designedly allocated to female nurses and establishing a supportive work environment (43) and organizational culture should be encouraged to prevent burnout among female nurses in China.

A previous study showed that age, gender, marital status, parental status, and professional title affected the incidence of burnout of female nurses (44). However, our study found that job characteristics, such as job tenure, monthly salary income, and night shift, were closely linked to the level of burnout, rather than age, marital status, and other demographic characteristics. The current study further confirmed that female nurses with shorter job tenure showed a greater vulnerability toward suffering burnout than those with longer job tenure. Compared to broad experienced female nurses, new female nurses may initially feel inadequately prepared for their occupational role, especially at the early stages of a career that often be known as the most stressful, frustrating, discouraging, and disillusioning stage for individual employees, which is also the process of ongoing professional role adaptation and identity crisis (45, 46). For female nurses with shorter job tenure, the experience of transition from school-based experience to professional practice can be stressful compounded by entrenched systemic issues, such as working irregular hours, rotating shifts, and under staffing (45). Being shorter job tenure, those nurses do not yet possess solid interpersonal and workplace relationships that are conducive to destroy intrapersonal psychological capital against burnout (47). Therefore, much more attention should be paid to that new female nurse is suffering from high-level burnout.

A previous study proved that inadequate sleep was associated with increasing burnout in shift working occupations (48). The current findings showed that working on night shifts is also one risk factor for female nurses suffering burnout rather than their weekly work hours. As an inevitable work type for providing in-patient nursing care, night shifts for female nurses were associated with more reports of heavy burnout symptoms (49, 50). A nurse working irregular shifts was more likely to lead to inadequate sleep (51), irregular habits and lifestyles (52), and change in sleep blood pressure (50), which in turn may explain the increased overall burnout risk among female nurses compared with those working daily (50). Inadequate sleep caused by irregular shifts might destroy accessibility and ability of female nurses to recover from fatigue caused by heavy duty and workplace demands, potentially resulting in the heightened burnout risk in those reporting irregular shifts (48). Unlike the western countries, the shortage of nurses in China is more serious due to the huge China population base and inefficient health service systems (53), thereby the nurses have been encountered heavier workload and more frequent irregular shifts, resulting in a range of serious consequences, such as sleep disorder and physical damage for a long time (54). Although shift work is unavoidable for a nursing career, it is valuable for a manager that optimizing shift arrangement in relation to control over overtime should be explored as one of the key intervention to prevent the high-level burnout among female nurses, thereby concentrating on improved health and wellness for female nurses and in turn enhanced patient care quality.

Female nurses with lower monthly salary income were more likely to report severe burnout than that those with higher monthly salary income, which seems to be at coherent with previous findings (55). To some extent, low salary is one of the key predictor for a high risk of burnout among female nurses might as a result of perceived disproportion between job resources and demands (56, 57). Perceived unreasonable revenue as an important determinant factor for female nurses is likely to lead to decreased motivation and job satisfaction and then resulting in high-level burnout (58), which also reversely interpreted that the participating female nurses in this study who reported high-level salary tend to feel less emotionally exhausted and less depersonalized but more personally accomplished. Besides, another reason might be that the general judgment indicator of PA of female nurses was determined by the money their earn (59). Previous studies revealed that Chinese nurses are dissatisfied with their salary (60), working environment, and nurse-patient relationships. Moreover, compared to the pre-COVID-19 epidemic stage, work pattern and workflow of nurse are completely different from the usual during controlling the COVID-19 epidemic. According to the current study, the finding suggested that 32.2% of the participants had hours/week more than 40 hours/week, indicating that nearly a third of the participants had complained the long working hours during the controlled COVID-19 period. In this stage, Chinese nurses are facing various huge challenges, such as increased the long working hours, extra effort, heavily workload, stress, new risk, and so on (20, 53). Except for front-line wards nurses, the majority of Chinese nurse's salary did not increase due to decreased hospital economic benefit during a fight against the COVID-19 epidemic period, which contributes to the effort-reward imbalance at work being more serious. Therefore, it is important for nurse administrators and managers to enable female nurses to alleviate work-related burnout symptoms through matching reasonably economic, physical, and emotional resources (61). The last evidence from The Dresden Burnout Study (DBS) is a 12-year longitudinal cohort study that aims to provide a description of the burnout syndrome on the basis of time and symptom criteria with a special focus on the search for biomarkers (62) indicated that providing work environments where high efforts are always linked with high rewards, such as economic, physical, and emotional resources, have to be considered an important issue for avoiding burnout (63).

In the current study, the findings need to be discussed with respect to certain limitations. First, data were collected through an online survey, which is prone to lead to response bias due to social desirability or negative effect. Second, although these efforts had been tried to ensure a representative sample and although there were no significant differences across data collection regions, we must acknowledge that the effective response rate was not ideal. Third, a cross-sectional design cannot determine a cause-effect relationship among the studied variables. Further experimental design is needed to test the cause-effect relationships across different cultural contexts. Forth, due to the substantial existence of income differences between the eastern and western areas in China, the categories of monthly salary incomes in our study only represent ordinal variables, which cannot explain the impact of the differences of real income between regions on burnout. Fifth, the multicollinearity problem is a substantial existence in our study, which potentially leads to skewed or misleading results when the current study attempts to determine how well each independent variable can be used most effectively to predict or understand the dependent variable in a statistical model. Last, burnout among nurses is constantly changing during the epidemic, but our study only focuses on a single time point in China from September to October 2020.