In this study, we identified three separate mental workload subtypes among nurses who had worked in hospitals during the COVID-19 outbreak. Of the 1337 nurses, the majority (62.5%) belonged to class 3 “high workload perception & low self-evaluation group”, who are most likely to be associated with longer professional years, more fatigue, better work engagement and higher COVID-19 exposure.
Self-perceived stress and mental demands are often underestimated using conventional objective workload indices, such as patient-to-nurse staffing ratios or patient acuity scores. The NASA-TLX is frequently used in emergency and Critical Care Units as a subjective measure of hospital staff workload and is supposed to be a stronger predictor of patient outcomes (Legenza et al., 2019). The generic version of the NASA-TLX contains six items that are marked on a twenty-point scale (Felton et al., 2012). Studies have suggested that a 4-item NASA-TLX may be more suitable for measuring nurse workload, however there is still controversy regarding the application of 4-item or 6-item versions of NASA-TLX in the clinical setting (Galy et al., 2018; Charles et al., 2019). Our current study utilized the 6-item version of NASA-TLX in order to assess different aspects of nurse workload. Our results demonstrated higher levels of perceived workload than previous studies in terms of the overall score of NASA-TLX (Young et al., 2008; Hoonakker et al., 2011), especially evident in those in class 3, which can be attributed to the heavier overload faced by Chinese nurses during the COVID-19 outbreak. Another characteristic of nurses in class 3 was the low self-evaluation scores, meaning that they felt more frustrated while working in the hospitals, and this can be partly explained by tense patient-nurse relationships and the higher risk of COVID-19 exposure during the outbreak. During working hours, nurses were required to wear personal protective equipment (PPE) for 6 hours or more of work, and coupled with the frequent and time-consuming process of putting on and taking off PPE, would have had adverse effects on the nurses’ mental burden (Huang et al., 2020).
Comparisons of demographic variables across different subgroups showed that nurses who were older and had longer professional years had a higher probability of belonging to class 3. This result is consistent with a previous study that showed employees over 36 years of age had heavier work pressure than those younger than 36 (Donders et al., 2012). How someone experiences workload may directly influence their own actions and responses. Older nurses are often imposed with increased responsibility, which may in turn lead to a heavier workload. However, in contrast to other previous findings (Tubbs-Cooley et al., 2018), our study showed that there were no gender differences between different subgroups, which may be attributed to the substantially lower proportions of male nurses.
Mental demand is often significantly higher when performing more difficult tasks, and therefore maximizing the available mental resources during difficult situations is crucial, especially when quick decisions need to be made. In order to further assess the impact of the COVID-19 outbreak exposure on nurses’ mental workload, we stratified all subjects to three categories according to the risk of virus exposure across different nursing units. Nurses with the highest exposure risk were those who had direct contact with confirmed COVID-19 positive patients (Huang et al., 2020). Group comparison results indicated that COVID-19 exposure contributed to significantly higher mental workload levels. A recent study showed that nurses showed excitability, irritability, unwillingness to rest, and signs of psychological distress in mobile hospitals (Chen et al., 2020). Thus, psychological interventions and assistance should be provided to nurses, whether online or face-to-face, in order to help decrease work-related stress.
Fatigue is also a critical factor involved in work-related errors and burnout (Yu et al., 2016). The prevalence of fatigue among healthcare workers varies between 21.6% and 91.9% (Cai et al., 2018). Our current study showed significant differences in fatigue among nurses belonging to the different subgroups. Multivariate analysis further demonstrated that high cognitive workload significantly increased the subjective assessment of fatigue, regardless of demographic variables such as age, gender, marital state and professional years. This result is in line with a previous study that showed excess cognitive workload resulted in fatigue, independent of inadequate sleep (Goel et al., 2014). Theoretically, high mental workloads can result in increased physical fatigue and mental distress in a clinical setting, which may negatively affect nurses’ work engagement (Austin et al., 2020). On the contrary, our current study showed that nurses with higher UWES scores belonged to the high workload perception & low self-evaluation group. Thus, there may be a potential positive correlation between nurses’ mental workload and work engagement. Moreover, a positive and supportive working environment can often accommodate nurses’ psychological needs and provide greater work engagement, which requires further investigation.