Latent profiles of work-related stress and their predictors
Given the huge strain and heavy workload of healthcare workers, especially during disease outbreaks [
6,
12,
34], it is of utmost importance to comprehensively investigate their work-related stress levels. The purpose of the current study was to establish whether distinct profiles of healthcare workers could be identified on the basis of their work-related stress levels during the COVID-19 pandemic, and if so, to examine sociodemographic and work-related predictors of profile membership.
Five latent profiles were identified based on the model fit indices and interpretability. Two of these profiles were homogenous: Profile 4 with low levels of stress (18.0%), and the most numerous Profile 2 (41.9%) with moderate levels of stress. The members of Profile 4 were younger than members of Profile 1 (“high stress with a good understanding of one’s job role”) and Profile 5 (“generally low stress but with very high job demands and relational conflicts”). The evidence on the role of age in work-related stress in healthcare workers is inconclusive [
1,
35]. In demanding situations such as the pandemic, increased stress may occur in older healthcare workers due to age-related burnout and decreased physical capacity to work intensively [
35]. Moreover, with increasing age, healthcare workers’ ability to adapt and tolerate a lack or insufficiency of job resources (such as autonomy on the job or feeling respected and fairly treated) may decrease, leading to higher work-related stress [
36].
The proportion of ED nurses to EMS staff was lower in profiles with moderate and lower levels of stress (i.e., Profiles 2 and 4) compared to Profile 3 (“relatively high stress with average demands and a very low understanding of one’s job role”). This result is supported by ED nurses’ higher levels of work-related stress for all domains except demands compared to EMS staff (see Table
3). These findings suggest that despite similar job demands, ED nurses may be more susceptible to increased stress during the pandemic than EMS staff due to lower job resources, such as poorer managers’ and colleagues’ support, lower job control, and less clear roles and responsibilities (see also [
11]).
In addition, members of Profiles 2 and 4 had fewer overtime hours per month than those in Profile 3 (“relatively high stress with average demands and a very low understanding of one’s job role”). This result is consistent with studies based on the variable-centered approach, which showed a positive relationship between the number of overtime hours and stress level [
37,
38]. The tremendous growth of the number of patients requiring care and treatment during the COVID-19 pandemic has significantly increased the workload of healthcare workers. What is more, some nurses had to go on sick leave due to the COVID-19 infection, which additionally contributed to the shortage of nursing staff. In such conditions, the remaining nurses had to work longer hours, which may have increased their work-related stress [
1,
39].
The remaining three profiles (i.e., Profiles 1, 3, and 5) turned out to be more diversified in terms of work-related stress than Profiles 2 and 4. The common feature of members of Profiles 1 and 3 is a relatively high total level of stress (see Fig.
1). The main difference between these profiles lies in the levels of demands and role clarity: despite high demands, members of Profile 1 understood their role and responsibilities quite well, knew their duties and tasks, and generally did not experience conflicting roles. By contrast, members of Profile 3 did not feel overworked but perceived their role as very unclear and ill-defined, with job tasks often extending their regular duties. Interestingly, in this profile, there was a higher proportion of ED nurses to EMS staff and a higher proportion of persons working in Ardabil city to those working in the countryside compared to Profile 1. During the pandemic, ED nurses and persons working in a large city may often face problems with role transparency, which may be related particularly to the lack of specific protocols and procedures in critical situations and staff shortages, resulting in the assignment of new tasks and duties, often requiring greater experience, skills and abilities than one possesses [
40]. In a crisis, ED nurses may also experience a role conflict stemming from the multiple and contradictory demands from supervisors, managers, doctors, and the executive staff [
22,
41]. The importance of role clarity in the stress level of healthcare workers was supported in a study conducted during the severe acute respiratory syndrome (SARS) epidemic in Hong Kong by Lam et al. [
25]. In that study, emergency room nurses reported that despite sufficient knowledge of their respective tasks, focusing on monitoring and preventing the disease instead of saving lives was related to conflict and role ambiguity, which in turn led them to stress. The results of the current study suggest that despite many challenges and unexpected and dangerous events often faced by EMS staff, their tasks and duties during the pandemic may be better structured and less conflicting than those performed by ED nurses. The importance of role clarity needs further investigation, especially since some data suggest that the role conflict may be the most important cause of job dissatisfaction among nurses [
42].
The least numerous Profile 5 was characterized by low levels of stress in most domains, except for demands and relationships, for which it was high. Interestingly, this profile included a higher proportion of single persons to married persons than Profile 1 (“high stress with a good understanding of one’s job role”) and Profile 3 (“relatively high stress with average demands and a very low understanding of one’s job role”). This result sheds some light on the contradictory findings of studies using the variable-centered approach concerning the role of marital status in work-related stress. On the one hand, in the present study, the proportion of married persons to single persons was higher for profiles with relatively high levels of stress (i.e., Profiles 1 and 3) than in Profile 5 (see Fig.
1). This result corroborates studies showing a positive correlation between being married and having a greater level of work-related stress, which may be primarily related to work-family conflicts [
43]. On the other hand, single persons seem to be more susceptible to experiencing stress caused by the combination of high demands and poor relationships, which may be the symptoms of workplace discrimination or bullying [
44,
45]. High demands noted in this group may be related to the potential unfair treatment of unmarried workers, such as giving them extra tasks and expecting them to be more available and ready to take night shifts, work overtime and on holidays than married workers [
45]. Interestingly, in a study by Kazi and Haslam [
24] on a sample of call center employees, Demands and Relationships were the only subscales of the HSE-MS IT negatively related to psychological well-being measured with the General Health Questionnaire-12 (GHQ-12). In light of the above, although Profile 5 was small (5.2%), further research on its specificity and mental functioning is highly recommended.