Nurses are one of the main pillars of healthcare systems [1]. Employment in healthcare settings requires high mental and cognitive abilities due to complex working conditions [2]. The complexity of job demands and constant mental engagement can lead to cognitive failures in nurses [3].

Cognitive failures are defined as lapses in attention, memory, or action that occur despite an individual's ability to perform tasks successfully under normal conditions [4]. These failures include disturbances in memory, decision-making, concentration, problem-solving, and communication [2]. Cognitive failures are a significant concern among nurses, with prevalence reported between 19.6 % and 29.1 % in some studies [5], [6]. They are closely associated with patient safety incidents [2], as lapses in concentration, rapid decision-making, and problem-solving can threaten patient health [7], [8].

Job content, which refers to the psychological and social aspects of work including decision authority, psychological job demands, physical exertion, physical isometric loads, job insecurity, supervisor support, and coworker support [3], can contribute to cognitive failures. Adapting to job content conditions can increase focus on nursing tasks and reduce such failures [5]. Factors such as high work speed and volume and lack of social support can create stress in an individual [9] and, by increasing perceived subjective workload, exacerbate cognitive failures in nurses [10].

Perceived subjective workload includes the physical, mental, and temporal demands imposed on an individual while performing work to achieve a certain level of performance, which is also related to the outcome of the work [11]. It is multidimensional, influenced by environmental, organizational, psychological, and individual cognitive factors [12]. Based on a meta-analysis study, 54 percent of nurses experience a high subjective workload perception, which is much higher among nurses working in the emergency department (ED) [13]. High workload perception is a major source of stress and burnout in nurses [14], [15], and insufficient time to perform care tasks can increase patient mortality [16].

Burnout, through the creation of emotional exhaustion and the induction of feelings of frustration and disappointment, can also be considered another effective factor in exacerbating cognitive failures in nurses [8]. According to Maslach's theory, burnout is a psychological syndrome leading to chronic fatigue, sleep disorders, physical symptoms, negative attitudes toward colleagues and patients, guilt, and reduced job performance [17].

Previous studies have shown relationships between job content, perceived subjective workload, job burnout, and cognitive failures. Mehri et al. (2020) reported significant associations between cognitive failures and job content subscales, including decision-making autonomy and job skills [3]. Athar et al. (2020) found strong relationships between cognitive failures and dimensions of job burnout, including emotional exhaustion, depersonalization, and personal accomplishment [8]. Jarahian Mohammady et al. (2018) reported a positive correlation between perceived subjective workload and occupational cognitive failures in intensive care unit nurses. Neglecting these factors may reduce nurses’ quality of life and threaten patient safety [11].

Previous studies have confirmed a relationship between perceived subjective workload [11], job burnout [8], and job content [3] with cognitive failures in nurses; however, their predictive power on these failures has not been investigated. Previous studies have examined the individual roles of job burnout, job content, and perceived subjective workload on cognitive failure; however, a comprehensive investigation of these factors has not been the focus of researchers.

Among nurses working in various departments, ED nurses are more susceptible to job burnout compared to other departments due to several factors such as high workload, long shifts, insufficient staffing, constant contact with critically ill and dying patients [18], and they endure a more intense work content [19].

Given the high prevalence of cognitive failures among emergency nurses [20] and the potential threats to patient safety [21], this study aims to identify how perceived subjective workload, job burnout, and job content contribute to cognitive failures in nurses. Understanding these relationships can inform interventions to improve nurses’ well-being, job satisfaction, and patient safety.

The study proposes the following hypotheses:

H1: Job content of ED nurses is related to and predicts their cognitive failures.

H2: Perceived subjective workload of ED nurses is related to and predicts their cognitive failures.

H3: Job burnout of ED nurses is related to and predicts their cognitive failures (Fig. 1).