The emergency department is a demanding and challenging working environment that requires provision of professional and emergency medical services to patients 24 h a day, 7 days a week [1]. As a result, nurses working in an emergency department usually face a variety of occupational stressors, including long working hours, interpersonal conflict, catastrophic accidents, the expectations of the patient’s companions, the unpredictable number of patients at any time, and urgent or violent situations [2]. The cumulative influence of these stressors can have detrimental effects on nurses’ physical and mental health, thereby leading to occupational burnout and depression [3], [4].

Role stress is conceptualized as any physical or mental stress experienced by a person who requires greater abilities or resources than those that are available in order to perform the role [5]. Emergency nurses play different roles (i.e., as patients’ caregivers, health promoters, and coordinators of the relationship between patients and medical staff) in their work lives. If nurses were not competent in assuming these different roles, many problems would result. The stress associated with these roles can cause role conflict, role ambiguity and role overload. Role conflict exists when a person faces a set of expectations, responsibilities and obligations from themselves, patients, colleagues, supervisors, administrators and others [6]. Role ambiguity occurs when the purposes and an individual’s responsibility to perform the role in an organization are vague [7]. Role overload occurs when people confront multiple obligations and requirements that force them to operate beyond their capacity at the time [8]. High role stress, which is a common and widespread phenomenon among medical staff, has major influences on individuals’ psychological health, including professional burnout, psychological distress, anxiety and depression [6], [9], [10], [11], [12]. Yang et al.’s systematic review of medical staff turnover intention literature has found a positive correlation between role stress and turnover intention [8]. According to Xiao et al., role stress is positively associated with burnout and psychological distress [12].

Burnout is a serious work-related psychological syndrome resulting from prolonged emotional or psychological stress [13]. It is characterized by three dimensions: emotional exhaustion, depersonalization and a reduced sense of personal accomplishment at work [14], [15]. Emergency medical staff have been found to have a higher level of burnout in comparison with other health providers[16], [17]. Burnout has become increasingly widespread among emergency medical staff, with a prevalence of 45–55 % among emergency medicine physicians 35–41 % and 40–44 % among emergency nurses [18], [19]. Occupational burnout imposes many negative consequences on emergency medicine workers, including high rate of turnover, job dissatisfaction, psychological distress and depression [20], [21], [22], [23], [24]. For example, Lee et al. found that burnout is a key factor influencing emergency nurses' intent to leave [23]. Among the 198 emergency medical staff, Abareshi et al. reported a significant statistical association between mental workload and occupational burnout [20]. Besides, the previous study on emergency department staff found a moderately strong negative correlation between level of job satisfaction and burnout [24].

Depression is considered a mental and behavioral disorder, and is characterized by persistent and recurrent sadness or lack of pleasure [25]. It has a negative impact on a person’s functional ability to work, learn or cope with daily life [26], [27]. The medical profession can be demanding and exposes nurses to work-related stress and depression. A Portuguese study has reported that more than 70 % of nurses in the COVID-19 pandemic had high levels of depression [28]. In another study, 34.3 % of nurses were found to have depression during the COVID-19 outbreak in China [29].

The importance of medical staff psychological health in contributing to patient safety outcomes is increasingly being recognized [30]. Several studies have found that medical staff burnout and depression are linked to staff mental health and patient safety outcomes [31], [32], [33], [34]. Emergency medical staff are considered to be at higher risk of developing burnout and depression than staff in other departments, because their job circumstances include long working hours, urgent or violent situations, and social pressures [17], [35]. Although extensive studies on burnout and depression among emergency nurses have identified a substantial association [19], [25], [35], [36], [37], very little information is available on the possible relationships among role stress, occupational burnout and depression. The estimation of occupational burnout, depression prevalence and the level of role stress among emergency nurses is essential for helping nurse administrators identify and alleviate the factors contributing to nurse distress in this vulnerable population. Therefore, the aims of our study were to estimate the prevalence of occupational burnout and depression among emergency nurses, and to identify the associations among role stress, occupational burnout and depression.