Prevalence and associated factors of secondary traumatic stress in emergency nurses: a systematic review and meta-analysis

ABSTRACT

Background: Nurses in emergency departments are at a high risk of experiencing secondary traumatic stress because of their frequent exposure to trauma patients and high-stress environments.

Objective: This systematic review and meta-analysis aimed to determine the overall prevalence of secondary traumatic stress among emergency nurses and to identify the contributing factors.

Method: We conducted a systematic search for cross-sectional studies in databases such as PubMed, Web of Science, Embase, CINAHL, Wanfang Database, and China National Knowledge Internet up to October 21, 2023. The Joanna Briggs Institute’s appraisal checklists for prevalence and analytical cross-sectional studies were used for quality assessment. Heterogeneity among studies was assessed using Cochrane’s Q test and the I² statistic. A random effects model was applied to estimate the pooled prevalence of secondary traumatic stress, and subgroup analyses were performed to explore sources of heterogeneity. Descriptive analysis summarized the associated factors.

Results: Out of 345 articles retrieved, 14 met the inclusion criteria, with 11 reporting secondary traumatic stress prevalence. The pooled prevalence of secondary traumatic stress among emergency nurses was 65% (95% CI: 58%–73%). Subgroup analyses indicated the highest prevalence in Asia (74%, 95% CI: 72%–77%), followed by North America (59%, 95% CI: 49%–72%) and Europe (53%, 95% CI: 29%–95%). Nine studies identified associated factors, including personal, work-related, and social factors. In the subgroup of divided by recruitment period, emergency department nurses in the COVID-19 outbreak period had a higher prevalence of secondary traumatic stress (70%, 95% CI: 62%–78%).

Conclusions: Secondary traumatic stress prevalence is notably high among emergency department nurses, with significant regional variations and period differences. The factors affecting secondary traumatic stress also varied across studies. Future research should focus on improving research designs and sample sizes to pinpoint risk factors and develop prevention strategies.

Registration: PROSPERO CRD42022301167.

HIGHLIGHTS

• Secondary traumatic stress is considered an occupational hazard for nurses. Emergency department nurses, in particular, face a greater risk of secondary traumatic stress compared to other professions.

• While various studies have investigated the prevalence of secondary traumatic stress among these nurses, findings have been inconsistent.

• The pooled prevalence of secondary traumatic stress among emergency nurses is 65%. Subgroup analysis by region shows that Asia experiences the highest combined prevalence at 74%, with North America at 59% and Europe at 53%. Emergency department nurses in the COVID-19 outbreak period had a higher prevalence of secondary traumatic stress (70%, 95% CI: 62%–78%).

Antecedentes: Las enfermeras en los departamentos de emergencia tienen un alto riesgo de experimentar estrés traumático secundario debido a su exposición frecuente a pacientes traumatizados y a entornos de alto estrés.

Objetivo: Esta revisión sistemática y metaanálisis tuvo como objetivo determinar la prevalencia general del estrés traumático secundario en las enfermeras de emergencia e identificar los factores contribuyentes.

Métodos: Realizamos una búsqueda sistemática de estudios transversales en bases de datos como PubMed, Web of Science, Embase, CINAHL, Wanfang Database y China National Knowledge Internet, hasta el 21 de octubre de 2023. Para la evaluación de la calidad se utilizaron los listados de verificación de evaluación del Instituto Joanna Briggs para estudios de prevalencia y estudios transversales analíticos. La heterogeneidad entre los estudios se evaluó mediante la prueba Q de Cochrane y el índice estadístico I2. Se aplicó un modelo de efectos aleatorios para estimar la prevalencia agrupada del estrés traumático secundario, y se realizaron análisis de subgrupos para explorar las fuentes de heterogeneidad. El análisis descriptivo resumió los factores asociados.

Resultados: De los 345 artículos recuperados, 14 cumplieron los criterios de inclusión, de los cuales 11 reportaron la prevalencia de estrés traumático secundario. La prevalencia agrupada de estrés traumático secundario en las enfermeras de urgencia fue del 65% (IC 95%: 58%-73%). Los análisis de subgrupos indicaron la prevalencia más alta en Asia (74%; IC 95%: 72%–77%), seguida de América del Norte (59%; IC 95%: 49%–72%) y Europa (53%; IC 95%: 29%–95%). Nueve estudios identificaron factores asociados, incluyendo factores personales, laborales y sociales. En el subgrupo dividido por período de reclutamiento, las enfermeras del departamento de emergencia en el período del brote de COVID-19 tuvieron una mayor prevalencia de estrés traumático secundario (70%; IC 95%: 62%–78%).

Conclusiones: La prevalencia del estrés traumático secundario es notablemente alta entre las enfermeras del servicio de emergencia, con importantes variaciones regionales y diferencias entre períodos. Los factores que afectan el estrés traumático secundario también variaron entre los estudios. Las investigaciones futuras deberían centrarse en mejorar los diseños de investigación y los tamaños de las muestras para identificar los factores de riesgo y desarrollar estrategias de prevención.

KEYWORDS:

• Meta-analysis
• nursing
• prevalence
• secondary traumatic stress
• emergency

PALABRAS CLAVE:

• Metaanálisis
• enfermería
• prevalencia
• estrés traumático secundario
• emergencia

1. Introduction

Secondary traumatic stress, first introduced by Figley in 1995, is defined as the behaviours and emotions that result from knowing about a traumatic event experienced by someone close (Figley, 1995). It refers to the stress from aiding or wanting to aid a traumatized person. Unlike post-traumatic stress disorder, which is caused by direct exposure to trauma, secondary traumatic stress arises indirectly, through contact with a traumatized individual, rather than the traumatic event itself.

Secondary traumatic stress has been used interchangeably with similar terms over the years, including burnout, compassion fatigue, and vicarious traumatization, causing some confusion in the field. Kellogg’s analysis of studies from 2010 to 2020, using Walker and Avant’s concept analysis process, showed that secondary traumatic stress was distinct from burnout and compassion fatigue, because the two terms did not require the antecedent of caring for individuals who experienced traumatic events (Kellogg, 2021). In addition, compassion fatigue and burnout do not have the psychological health consequences of secondary traumatic stress (Kellogg, 2021). Gusler used correlation and network analysis to indicate that secondary traumatic stress and vicarious traumatization were two related but unique constructs (Gusler et al., 2023). Arnold, using Rodgers’ evolutionary approach, describes secondary traumatic stress as akin to post-traumatic stress disorder, categorizing its symptoms into four dimensions: central, physical, psychological, and social (Arnold, 2020). The central dimension is the occurrence of post-traumatic stress disorder-like symptoms. The physical dimension includes difficulty breathing, exhaustion, somatic complaints, and eight other symptoms, the most commonly listed is difficulty sleeping. Persistent anxiety and distressing emotions are two of the most mentioned psychological symptoms. The social dimension includes apathy, difficulty with trust and intimacy, and defensiveness (Arnold, 2020).

Healthcare providers closer to patient trauma events have a higher risk of screening positive for secondary traumatic stress symptoms (Luftman et al., 2017). Studies have indicated that secondary traumatic stress poses numerous risks to nurses and is considered an occupational hazard (Barleycorn, 2019). Emergency department nurses admit critically ill patients and provide on-site emergency treatment for major public crises such as earthquakes, car accidents, fires, and epidemics. These patients are often in critical condition, requiring urgent and dynamic interventions, which places high pressure on nurses and demands a rapid work pace in a complex environment. The unique nature of this profession frequently exposes nurses to traumatic situations and the care of trauma-affected patients. The prevalence of secondary traumatic stress among emergency department nurses in most studies is over 60% (Ariapooran et al., 2022; İlhan & Küpeli, 2022; Li et al., 2023; Salameh et al., 2023; Wolf et al., 2020), higher than 50.3% among pediatric nurses (Kellogg et al., 2018), 38% among oncology nurses (Quinal et al., 2009), 35% among delivery nurses (Nicholls et al., 2021), and 12.7% among emergency medicine clinicians (Roden-Foreman et al., 2017), which indicate that emergency nurses are more vulnerable to secondary traumatic stress.

Secondary traumatic stress is linked to adverse health outcomes in psychological, interpersonal, and organizational domains. Psychologically, nurses with secondary traumatic stress are at increased risk for severe anxiety, depression, and compassion fatigue (Dominguez-Gomez & Rutledge, 2009). Interpersonally, those affected by secondary traumatic stress may experience changes in their emotional connections with patients, family, friends, and colleagues, and may face difficulties such as self-isolation (Barleycorn, 2019). Organizationally, nurses with high levels of secondary traumatic stress exhibit poor job performance (Von Rueden et al., 2010), and a higher risk of medical errors and increased absenteeism (Suárez et al., 2017), which can lead to burnout, low job satisfaction (Caricati et al., 2014), and a higher turnover rate (Duffy et al., 2015; Mealer & Jones, 2013). Therefore, understanding and addressing secondary traumatic stress is essential for the occupational health of emergency department nurses and the safety of their patients.

The Professional Quality of Life Scale and the Secondary Traumatic Stress Scale are commonly used tools for measuring secondary traumatic stress. The Professional Quality of Life Scale was developed by Dr. Stamm in 2010 and is designed to evaluate the professional quality of life of helpers, including compassion satisfaction and compassion fatigue, which are composed of burnout and secondary traumatic stress (Stamm, 2010a). Barré believed that compassion fatigue, burnout, and secondary traumatic stress were similar but differed, and the Professional Quality of Life Scale was more suitable for evaluating the overall professional quality of life of helpers rather than individual evaluations of secondary traumatic stress (Barré & Hooper, 2023). Kellogg also believed that these three terms had conceptual differences, and secondary traumatic stress was not a component of compassion fatigue; accordingly, researchers should avoid using the Professional Quality of Life Scale to measure secondary traumatic stress (Kellogg, 2021). The Secondary Traumatic Stress Scale was developed by Bride in 2004 and includes three subscales: intrusion, avoidance, and arousal (Bride et al., 2004). It was considered the only scale subject to robust peer review and the only single concept scale specifically designed for caregivers’ traumatic experiences (Beck, 2011; Watts & Robertson, 2015).

In recent years, research on the prevalence and factors linked to secondary traumatic stress among emergency department nurses has grown, yet findings have been inconsistent. The prevalence of secondary traumatic stress among nurses in the emergency department varied from 38.75% to 77.25% (Dirk, 2021; Dominguez-Gomez & Rutledge, 2009; Duffy et al., 2015; Li et al., 2023; Ratrout & Hamdan-Mansour, 2020; Salameh et al., 2023). Li’s study showed that education level was negatively correlated with secondary traumatic stress (Li et al., 2023), whereas Salameh and Subih showed no correlation between the two (Salameh et al., 2023; Subih et al., 2023). Dirk's study showed a negative correlation between social support and secondary traumatic stress score (Dirk, 2021), whereas Salameh and Ratrout's results showed no correlation (Ratrout & Hamdan-Mansour, 2020; Salameh et al., 2023). Additionally, inconsistencies also existed in the studies on clinicians (Elwood et al., 2011).

To the best of our knowledge, no meta-analysis investigates the prevalence of secondary traumatic stress in emergency nurses. This systematic review aims to determine the prevalence of secondary traumatic stress and explain factors associated with secondary traumatic stress among emergency nurses.

2. Methods

This systematic review was conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guideline (Page et al., 2021). The study protocol was registered in PROSPERO (CRD42022301167).

2.1. Literature search strategy

A comprehensive search was carried out in both Chinese and English-language databases up to October 21, 2023. This included the China National Knowledge Infrastructure Database, Wanfang Database, PubMed, PsycINFO, Embase, CINAHL, and Web of Science. We developed our search strategy using key terms such as ‘secondary traumatic stress,’ ‘secondary trauma*,’ and ‘emergency nursing.’ The details of the search strategy can be found in Supplementary Material Table 1. Additionally, manual searches were conducted to find related studies by checking reference lists.

Table 1. Characteristics of the included studies.

Author	Country/geographical region	Data years	Sample	Inclusion criteria and exclusion criteria	Age Mean	Scale	Diagnostic criteria	Mean score of STSS	Prevalence of STS	Associated factors of STS
Salameh et al., 2023	Palestine/Asia	January to March, 2021	189	Inclusion criteria: had a certification in nursing; had a minimum of 6 months of experience in the EDs 21 years of age and above. Exclusion criteria: nursing students, nurses that were newly transferred to the EDs or those who worked part-time, and head nurses	–	STSS (Bride et al., 2004)	≥38	47.02	77.25%	1. Longer years of experience were associated with higher STS (β = 3.6, p = .03). 2. Higher perceived stress was associated with higher STS (β = 1.31, p < .001). 3. Higher burnout was associated with higher STS (β = 0.399, p < .001). 4. Gender, age, marital status, level of education, type of hospital, providing care for a COVID-19 patient in ED, job satisfaction and perceived social support were not associated with STS.
Li et al., 2023	China/Asia	January, 2022	213	Inclusion criteria: had a minimum 6 months of experience in the EDs Exclusion criteria: During the investigation, go out to study, vacation, etc.	–	STSS Chinese version	<25 little or no STS; 28–37: mild STS; 38–43: moderate STS; 44–48 severe; ≥ 49: extremely severe STS	33.17	72.77%	1. Longer working years were associated with lower STS (β = −0.328, p < .001). 2. Nurses who were divorced or widowed were associated withlower STS levels (β = −0.130, p = .038). 3. Nurses who consider changing careers were associated with higher STS levels (β = 0.195, p = .004) 4. Nurses who had taken sick leave in the past year were associated with higher STS levels (β = 0.147, p = .017). 5. Average income per person in a family and job satisfaction were not associated with STS.
Subih et al., 2023	Jordan/Asia	March to April, 2018	203	Registered nurses working full-time in the emergency department with at least one year	29	ProQOL Version 5 (Stamm, 2005)	≤ 22: low STS, 23–41: moderate STS; ≥ 42: high STS	29.7	–	1. Comorbidities were associated with lower STS. (r = −0.16, p < .05) 2. Age, gender, educational level, marital status, smoking, BMI, type of hospital, years of experience in ED, and shift length were not associated with STS.
Ariapooran et al., 2022	Iran/Asia	2020	110	All nurses working at three hospitals in Malayer city	–	STSS Persian version	≥38	38.90	62.27%	–
İlhan & Küpeli, 2022	Turkey/Asia	April to May, 2021	252	Emergency nurses who gave informed consent	–	STSS Turkish version (Yildirim et al., 2018)	≥38	–	74.60%	–
Lopez et al., 2022	United States/North America	May to June, 2021	50	Registered nurse who was actively working on the ED and hired before January 2021	–	ProQOL Version 5 (Stamm, 2009–2012)		24.5	–	1. Higher burnout was associated with higher STS (r = 0.54, p < .001). 2. Nurses working the midshift were associated with higher STS (t = 2.915, p = .007) 3. Marital status, No. of children living in the home, years of experience, age range, hospital location, full time equivalent were not associated with STS.
Dirk, 2021	Canada/North America	May to July, 2020	260	Inclusion criteria: registered nurse, currently providing direct patient care ≥ 6 months; Exclusion criteria: nurse managers and licensed practical nurses	38	STSS (Bride et al., 2004)	≥38	40.70	56.50%	1. Higher support from outside of work (B = −0.046 p < .001) and organizational support (B = 1.16 P < .001) were associated with lower STS. 2. Length of Shift, full-time equivalent, colleague support and direct supervisor support were not associated with STS.
Yearwood, 2021	United States/North America	August to December, 2020	89	Inclusion criteria: registered nurses who worked in the ED in the United States. Exclusion criteria: advanced practice registered nurses who worked in the ED for <1 year or worked less than 30 h per week	–	ProQOL (Stamm, 2010b)		–	–	Higher emotional intelligence was associated with lower STS (B = −0.176; p < .003)
Wolf et al., 2020	United States/North America	August to September, 2019	125	English-speaking registered nurses over the age of 18	–	STSS (Bride et al., 2004)	≥39	49.75	76%	–
Ratrout & Hamdan-Mansour, 2020	Jordan/ Asia	January to August, 2017	202	Employed as a nurse in an ED for ≥ 6 months; providing direct patient care as part of daily assignments; ability to speak Arabic as a native language	27.9	STSS Arabic version	≥38	46	74.75%	1. Higher coping was associated with higher STS (β = 0.316, p < .001). 2. Higher empathy was associated with lower STS (β = −0.163, p = .016). 3. Social support, history of trauma (The Life Events Checklist), exposure to trauma (average percentage of time you spent in providing direct and indirect care to traumatized patients) and organizational support were not associated with STS.
Penson, 2019	United States/North America	–	56	Work in an ED and are members of a local North Carolina chapter of the Emergency Nurses Association	–	STSS (Bride et al., 2004)	≥38	36.45	51.79%	–
Morrison & Joy, 2016	UK/ Europe	2013	80	Inclusion criteria: all emergency nurses in four hospitals’ EDs in the West of Scotland Exclusion criteria: nurses working in the ED for less than a year and less than 18 years old	40	STSS (Bride et al., 2004)	≥38	37.4	38.75%	–
Duffy et al., 2015	Ireland/ Europe	February, 2013	105	All registered nurses working in three EDs attached to public teaching hospitals in the Western region of Ireland	40	STSS (Bride et al., 2004)	≥38	45.98	70%	1. Change of career considered was associated with higher STS (OR = 3.9, p = .017). 2. Nurses find alcohol helpful in alleviating work-related stress was associated with higher STS (OR = 4.4, p = .004). 3. Higher peer support was associated with higher STS (OR = 5.8, p = .020). 4. Marital status, highest educational level, exercise, hobbies, member of a professional body, and finds a best friend/mentor helpful in alleviating work-related stress were not associated with STS.
Dominguez-Gomez & Rutledge, 2009	United States/ North America	–	67	RNs with a minimum of 6 months experience in the ED	43	STSS (Bride et al., 2004)	≥38	–	50%	1. Female was associated with higher STS (t = 5.447, p = .023). 2. Shift worked, use of counselling, use of stress management strategies, ethnicity, and highest level of education were not associated with STS.

Note. STS: Secondary Traumatic Stress; STSS: The Secondary Traumatic Stress Scale, ProQOL:The Professional Quality of Life; ED: Emergency Department

2.2. Inclusion and exclusion criteria

Studies qualified for inclusion if they: 1) involved emergency department nurses (registered nurses); 2) adopted commonly used secondary traumatic stress measurement tools, including the Secondary Traumatic Stress Scale and the Professional Quality of Life; 3) reported mean or median scores, prevalence, or factors related to secondary traumatic stress, or provided enough raw data for calculations; 4) were observational studies (cohort, case-control, or cross-sectional); and 5) were published in either Chinese or English. Exclusion criteria applied to studies that: 1) had mixed samples of emergency healthcare workers, without separate data for nurses; and 2) lacked accessible full text.

2.3. Study selection and data extraction

Duplicate studies were removed using the EndNote library (Version 20, Clarivate, Philadelphia, PA, USA). Three reviewers (BZ, XW, ZZ) independently screened the studies by title and abstract. Those that met the established criteria were selected through a full-text review and analysis. Any disagreements between the reviewers were settled through consensus or by consulting a third reviewer (MZ). Two researchers (ZX, JY) independently created a standardized form to extract information from the included studies, detailing the author, country/geographical region, data years, sample, age mean, scale, diagnostic criteria, mean score of the Secondary Traumatic Stress Scale, associated factors, and prevalence of secondary traumatic stress. The researchers resolved any discrepancies through discussion.

2.4. Quality assessment

Four reviewers (ZX, BZ, XW, JY) independently evaluated the risk of bias in the included studies using the Joanna Briggs Institute’s critical appraisal checklist designed for prevalence data studies (Munn et al., 2015). This checklist includes nine items with response options ‘Yes,’ ‘No,’ ‘Unclear,’ and ‘Not applicable,’ a method commonly used in meta-analysis articles focused on prevalence. The same checklist, with eight items, was used to assess analytical cross-sectional studies (Moola et al., 2020). If any disagreements arose, another author (MZ) was consulted to achieve consensus.

2.5. Data analyses

Analyses of data were conducted using the metaprop module in R software version 4.0.5. We calculated the pooled prevalence of secondary traumatic stress in emergency nurses using a log transformation random-effects model, with a 95% confidence interval. To evaluate heterogeneity among the studies, we employed Cochrane's Q test and the I² statistic, considering a p-value of .05 as the threshold for statistical significance. I² values of 25%, 50%, and 75% indicated low, moderate, and high heterogeneity, respectively (Huedo-Medina et al., 2006). Subgroup analyses were performed to explore the effect of geographical region and recruitment period on secondary traumatic stress prevalence as potential sources of heterogeneity. We assessed publication bias using Egger’s test (Sterne et al., 2000). Descriptive analysis was used to summarize factors related to secondary traumatic stress, because the data from the included studies were not suitable for pooling.

3. Results

3.1. Selection and characteristics of studies

A search of the databases yielded 339 studies, with 94 being duplicates (Figure 1). After screening titles and abstracts, 222 articles were excluded based on the inclusion and exclusion criteria, and an additional nine were excluded after full-text review. Six additional articles were identified through citation searches. Ultimately, 14 studies were included in this review, as shown in Table 1. These studies were published between 2009 and 2023, with five originating from the United States, two from Jordan, and one each from seven other countries. Eleven studies assessed the prevalence of secondary traumatic stress in emergency nurses, with findings ranging from 38.75% to 77.25%, using the Secondary Traumatic Stress Scale and a threshold of 38 or 39. Eight articles examined factors affecting secondary traumatic stress, using tools such as the Secondary Traumatic Stress Scale and the Professional Quality of Life Scale to measure secondary traumatic stress.

Figure 1. Flowchart of study selection.

3.2. Quality assessment

The Joanna Briggs Institute’s critical appraisal checklist for prevalence data was applied to 11 studies, and a checklist for cross-sectional studies was used for three studies. The outcomes of the quality assessment for all included articles can be found in Table 2 and Table 3. Most of the literature reviewed scored ‘yes’ on over six items, signifying high quality. However, a significant shortcoming was the insufficient response rate and the failure to identify and manage confounding factors.

Table 2. Quality assessment of studies reporting prevalence data (n = 11).

Study author and year	1. Was the sample representative of the target population?	2. Were study participants recruited in an appropriate way?	3. Was the sample size adequate?	4. Were the study subjects and setting described in detail?	5. Was the data analysis conducted with sufficient coverage of the identified sample?	6. Were valid methods used for the identification of the condition?	7. Was the condition measured in a standard, reliable way for all participants?	8. Was there appropriate statistical analysis?	9. Was the response rate adequate, and if not, was the low response rate managed appropriately?	Total number of ‘yes’
Salameh et al., 2023	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	9
Li et al., 2023	Yes	Yes	No	Yes	Yes	Yes	Yes	Yes	Yes	8
Ariapooran et al., 2022	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	9
İlhan & Küpeli, 2022	Yes	No	Yes	No	Yes	Yes	Yes	Yes	Yes	7
Dirk, 2021	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Unclear	8
Wolf et al., 2020	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	No	8
Penson, 2019	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	No	8
Ratrout & Hamdan-Mansour, 2020	Yes	No	No	Yes	No	Yes	Yes	Yes	No	5
Morrison & Joy, 2016	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	No	8
Duffy et al., 2015	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	9
Dominguez-Gomez & Rutledge, 2009	Yes	Unclear	Yes	Yes	Yes	Yes	Yes	Yes	No	7

Table 3. Quality assessment of analytical cross sectional study (n = 3).

Study author and year	1. Were the criteria for inclusion in the sample clearly defined?	2. Were the study subjects and the setting described in detail?	3. Was the exposure measured in a valid and reliable way?	4. Were objective, standard criteria used for measurement of the condition?	5. Were confounding factors identified?	6. Were strategies to deal with confounding factors stated?	7. Were the outcomes measured in a valid and reliable way?	8. Was appropriate statistical analysis used?	Total number of ‘yes’
Subih et al., 2023	Yes	Yes	Yes	Yes	No	No	Yes	Yes	6
Lopez et al., 2022	Yes	Yes	Yes	Yes	No	No	Yes	Yes	6
Yearwood, 2021	Yes	Yes	Yes	Yes	No	No	Yes	Yes	6

3.3. Prevalence of secondary traumatic stress in emergency nurses

A total of 11 studies used the Secondary Traumatic Stress Scale to report prevalence. Within these, eight articles set the threshold at 38. Li et al. (2023) and Wolf et al. (2020) used cut-off scores of 28 and 39, respectively, and the data provided in the studies were insufficient to calculate the prevalence at a cut-off value of 38. Ratrout and Hamdan-Mansour (2020) also use a cut-off of 28; however, we calculated the prevalence of secondary traumatic stress using a cut-off value of 38 based on the data provided in the study, following the criterion established by Bride et al. (2004) that a score of 38 or higher indicates the presence of secondary traumatic stress. The combined prevalence of secondary traumatic stress among emergency nurses was 65% (95% CI, 58%–73%), using a random-effects model meta-analysis owing to significant heterogeneity (I² = 84%, p < .01), as shown in Figure 2.

Figure 2. Meta-analysis on the prevalence of STS.

3.4. Subgroup analyses

Subgroup analyses were conducted based on geographical region, as shown in Figure 3. The studies included four from Asia, four from North America, and two from Europe, with total populations of 966, 508, and 185, respectively. The results of the random effects model meta-analysis revealed that Asia had the highest pooled prevalence of secondary traumatic stress at 74% (95% CI: 72%–77%), followed by North America at 59% (95% CI: 49%–72%) and Europe at 53% (95% CI: 29%–95%). In addition, we used December 2019 as the time point to divide the included studies into two groups according to the recruitment period: before and after the COVID-19 outbreak. As shown in Figure 4, emergency department nurses in the outbreak period had a higher prevalence of secondary traumatic stress (70%, 95% CI: 62%–78%).

Figure 3. Meta-analysis on geographical region.

Figure 4. Meta-analysis on recruitment time.

3.5. Associated factors of secondary traumatic stress

Owing to the variety of influencing factors, we used descriptive analysis to categorize them into three main areas: personal, work-related, and social factors. There were a total of 25 personal factors. Gender was not associated with secondary traumatic stress in Salameh et al.’s and Subih et al.’s studies (Salameh et al., 2023; Subih et al., 2023), whereas the study by Dominguez-Gomez and Rutledge showed that female have higher secondary traumatic stress (Dominguez-Gomez & Rutledge, 2009). Li et al.’s finding suggested that divorced or widowed nurses were associated with lower secondary traumatic stress (Li et al., 2023), whereas in the other four studies, marital status was not associated with secondary traumatic stress (Duffy et al., 2015; Lopez et al., 2022; Salameh et al., 2023; Subih et al., 2023). There was a positive correlation between comorbidities, coping, and alcohol consumption to alleviate stress, and secondary traumatic stress levels (Duffy et al., 2015; Ratrout & Hamdan-Mansour, 2020; Subih et al., 2023). Empathy and emotional intelligence were negatively correlated with secondary traumatic stress (Ratrout & Hamdan-Mansour, 2020; Yearwood, 2021). Salameh et al. and Li et al. offered opposing results on the relationship between working years and secondary traumatic stress (Li et al., 2023; Salameh et al., 2023), whereas two other studies show no correlation between the two (Lopez et al., 2022; Subih et al., 2023). In addition, age, ethnicity, number of children living with, education level, hospital location and type, full-time equivalent, average income, traumatic experience, smoking, BMI, exercise, hobbies, membership in a professional body, use of counselling and stress management strategies, and caring for COVID-19 patients were not associated with secondary traumatic stress in the studies (Dirk, 2021; Dominguez-Gomez & Rutledge, 2009; Duffy et al., 2015; Li et al., 2023; Lopez et al., 2022; Ratrout & Hamdan-Mansour, 2020; Salameh et al., 2023; Subih et al., 2023).

There were 11 work-related factors. Burnout, perceived stress, considerations of changing careers, peer support, sick leave, and midshift were positively correlated with secondary traumatic stress levels (Dirk, 2021; Duffy et al., 2015; Li et al., 2023; Lopez et al., 2022; Salameh et al., 2023). Organizational support was negatively correlated with secondary traumatic stress in Dirk et al.’s study (Dirk, 2021), but showed no association in Ratrout and Hamdan-Mansour’s study (Ratrout & Hamdan-Mansour, 2020). Job satisfaction, shift length, support from colleagues and direct supervisor, and shift work were not related to secondary traumatic stress (Dirk, 2021; Dominguez-Gomez & Rutledge, 2009; Li et al., 2023; Salameh et al., 2023; Subih et al., 2023). Dirk's study showed that higher levels of social support were associated with lower secondary traumatic stress (Dirk, 2021), while the other three studies showed no relationship (Duffy et al., 2015; Ratrout & Hamdan-Mansour, 2020; Salameh et al., 2023). These factors are summarized in Table 1.

3.6. Sensitivity analysis and publication bias

A sensitivity analysis was conducted, revealing that the pooled prevalence remained stable, even when each study was excluded one by one. Additionally, Egger’s test indicated the presence of publication bias (t = −4.32, p < .01) and the funnel plot apparent asymmetry, as illustrated in Figure 5.

Figure 5. Funnel plot.

4. Discussion

To the best of our knowledge, this is the first systematic review and meta-analysis examining the prevalence of secondary traumatic stress among emergency department nurses. The pooled prevalence rate was 65%, with contributing factors, such as personal characteristics, work-related issues, and social support, identified in the studies reviewed.

Despite emergency nurses being more likely to encounter trauma, violence, and rescue situations, putting them at a greater risk for secondary traumatic stress, there is limited research on its prevalence. This study reviewed 11 studies on secondary traumatic stress prevalence, finding it to be higher among emergency nurses than among pediatric nurses (Kellogg et al., 2018), midwives (Nicholls et al., 2021), and emergency medicine clinicians (Roden-Foreman et al., 2017). All studies used the Secondary Traumatic Stress Scale, a specialized tool for secondary traumatic stress screening. A score of 38 or higher is typically indicative of secondary traumatic stress, but the criteria vary across the 11 studies.

Subgroup analyses revealed that emergency nurses in Asia experienced the highest prevalence of stress, followed by those in North America and Europe. This aligns with the findings of Xie et al., which showed that nurses in Asia had the highest secondary traumatic stress pooled mean score (Xie et al., 2021). Considering Asia’s population represents approximately 60% of the world’s total (United Nations, 2022), the region’s rapid economic growth, urbanization, and an aging population have intensified the demand for both quality and quantity in healthcare. This has exacerbated the existing nurse shortage and uneven distribution (World Health Organization, 2020), placing additional stress on Asian nurses (Woo et al., 2020). The limited research on secondary traumatic stress among emergency nurses in Europe suggests a potential sample size bias. In addition, differences in inclusion criteria of participants and cut-off point of the Secondary Traumatic Stress Scale may also contribute to significant heterogeneity in the subgroups of North American and European subgroups. Another subgroup analysis showed a higher prevalence of secondary traumatic stress among nurses in studies conducted during the COVID-19 pandemic. Emergency department nurses played an indispensable role in the response to the COVID-19 outbreak (Quah et al., 2020). They were one of the first-line healthcare providers who regarded all patients as potentially COVID-19 infection, and responsible for the treatment of acute and critical patients inside and outside the hospital, leading them to face burgeoning workloads, psychological distress, emotional exhaustion, and a higher risk of trauma event exposure (Hesselink et al., 2021; Nie et al., 2020). However, due to the significant heterogeneity of the result, it should be interpreted with caution.

Eight personal factors influenced secondary traumatic stress, with emotional intelligence showing a negative correlation (Yearwood, 2021). Emotional intelligence is crucial for enhancing nurses’ psychological wellbeing because those with higher emotional intelligence are better equipped to handle demanding work environments (Lee & Sim, 2021). Interventions targeting emotional intelligence have proven effective in bolstering nurses’ psychological resources and their ability to manage work-related stress (Liu et al., 2023; Saikia et al., 2023). The relationship between gender and secondary traumatic stress remains controversial. Though the number of men in emergency departments is increasing, emergency departments are mainly female. Studies indicated that identifying as a female nurse was associated with higher levels of stress (Dominguez-Gomez & Rutledge, 2009; Kakemam et al., 2019; Soto-Castellón et al., 2023), but other studies showed no association (Salameh et al., 2023; Subih et al., 2023). This may be related to the difference in sample size and the number of males and females. The prevalence of secondary traumatic stress was higher among emergency department nurses compared to nurses in ICU/CCU, medical emergency, and other wards (Ariapooran et al., 2022), and the frequency of exposure to patient-related stress events is positively correlated with stress-related outcomes (de Wijn & van der Doef, 2020), which is more likely to lead to secondary traumatic stress (Kitano et al., 2023). Coping ability is a key protective factor for emergency department nurses facing secondary traumatic stress, helping to mitigate the psychological effects of traumatic events. İlhan and Küpeli (2022) found that positive coping strategies were linked to lower secondary traumatic stress levels in emergency medical staff, whereas Ratrout and Hamdan-Mansour (2020) reported a positive association between coping and secondary traumatic stress. Viewing alcohol as a stress reliever is considered a maladaptive coping mechanism, potentially intensifying nurses’ negative emotions (Foli et al., 2020; Vancampfort & Mugisha, 2022). The mental health of individuals worsens with an increase in comorbidities, especially among the young as it challenges their coping capacities (Tong et al., 2021). The relationship between years of service and secondary traumatic stress remains debatable, as does the effect of empathy (Crumpei & Dafinoiu, 2012) and marital status (Bahari et al., 2022). Currently, conclusions about the link between included factors and secondary traumatic stress among emergency department nurses are inconsistent which may be due to the following aspects: First, there is a lack of clarification on the concept of secondary traumatic stress in the existing research. Kellogg believed that compassion fatigue and burnout did not have psychological health consequences for secondary traumatic stress, and researchers should avoid using the Professional Quality of Life Scale to measure secondary traumatic stress (Kellogg, 2021). Second, the secondary traumatic stress diagnostic criteria are inconsistent, with the cut-off values including 28, 38, and 39. Although we recalculated prevalence according to 38 points for studies with sufficient data to reduce the differences, the statistical results cannot be recalculated. Third, the statistical methods differ. In terms of the exploration of influencing factors, the methods used in the included literature involved linear regression, t-test, and logistics regression.

Emergency departments worldwide face significant challenges, including managing a broad spectrum of trauma events and providing immediate care to critically ill patients. Nurses in these departments encounter greater treatment challenges and work pressure, leading to higher burnout rates and a greater intention to leave the job compared to other specialties (McDermid et al., 2020; O'Callaghan et al., 2020). These factors contribute to secondary traumatic stress levels. Shift work, which disrupts circadian rhythms, adds to the work pressure, increasing the risk of sleep disorders and cardiovascular issues among nurses (Rosa et al., 2019). Consequently, nurses may need more time to recover from shifts and are more susceptible to developing secondary traumatic stress. The literature shows inconsistent findings regarding the relationship between shift work and secondary traumatic stress, possibly because of variations in shift patterns and lengths. Studies have shown that high occupational hazards can lead to worsening health and increased sick leave, diminishing the ability to cope with traumatic events (Canadian Federation of Nurses Unions, 2020). Support from organizations, colleagues, and the community positively affects coping skills, resilience, and happiness (Cohen et al., 2023; Ruiz-Fernández et al., 2021; Sprang et al., 2021; Velando-Soriano et al., 2020), which can mitigate negative emotions among nurses and buffer against the development of secondary traumatic stress.

While the factors included in the study were personal, work, and social, the design used to explore secondary traumatic stress factors in emergency department nurses seemed inadequate to capture the whole aspect of this phenomenon. The systematic review by Ratrout and Hamdan-Mansour highlighted a lack of research on the relationship between clinical supervision, organizational culture, and organizational resources and secondary traumatic stress (Ratrout & Hamdan-Mansour, 2017). One of the most important concepts directly related to secondary trauma stress is the Ecological Framework of Trauma developed by Dutton and Rubinstein (Dutton and Rubinstein, 1995), which conceptualizes four elements of secondary traumatic stress occurrence: 1) exposure to traumatic events; 2) coping strategies for responding to the traumatic situation, including cognitive and behavioural efforts; 3) post-traumatic reactions, including psychological distress, changes in assumptions and beliefs about the world, and relationship disorders; and 4) personal factors, including personal resources (especially high self-esteem), professional resources (experience, training), vulnerability (trauma history), and satisfaction with personal and professional life, and environmental factors, including social support and working environment. The rationale behind the included studies’ selections of variables is not clear and is not based on a theoretical framework. Further research is needed to explore factors influencing the occurrence of secondary traumatic stress in emergency department nurses.

In addition to emergency department nurses, the secondary traumatic stress investigation focuses on nurses working in oncology, pediatrics, trauma centres, and medical personnel who provide medical support to trauma victims, those are more likely to be exposed to traumatic events and indicated higher secondary traumatic stress prevalence (Kellogg et al., 2018; Ogińska-Bulik et al., 2021; Woo & Kim, 2021; Yehene et al., 2024). The influencing factors also include personal, work, and social dimensions, but vary according to the requirements of the job. The research designs related to secondary traumatic stress are mostly cross-sectional studies, and the selection of variables lacks theoretical support. Future studies should be improved to provide evidence for the occurrence and progression of secondary traumatic stress in healthcare professionals.

5. Strengths and limitations

Our review represents the first meta-analysis examining the prevalence of secondary traumatic stress among emergency department nurses, using a thorough search strategy. Though there is heterogeneity and publication bias in the study, there is no significant difference between the sensitivity analysis and the results, which to some extent enhances the reliability of the results. However, it is important to acknowledge certain limitations. First, while secondary traumatic stress prevalence was assessed using the Secondary Traumatic Stress Scale, inconsistencies in cut-off values must be considered when interpreting the data. Second, the studies included showed significant heterogeneity, and consideration may be given to differences in study design, such as scale with other versions and lack of verification, cut-off values, regions, and measurement time points. Third, the included studies are all cross-sectional, and the results cannot verify the causal relationship between variables and secondary traumatic stress. Fourth, despite including studies in both English and Chinese, publication bias may still be present. These limitations warrant further study.

6. Conclusions

This systematic review encompassed 14 cross-sectional studies, with 11 indicating the prevalence of secondary traumatic stress. The pooled prevalence rate stood at 65%, and a regional subgroup analysis revealed that secondary traumatic stress was most prevalent among emergency department nurses in Asia, with North America and Europe following. Meanwhile, the prevalence of secondary traumatic stress was also higher in nurses who experienced the COVID-19 pandemic. Factors such as personal characteristics, work-related elements, and social support were linked to secondary traumatic stress, although the findings varied. Healthcare managers and policymakers must provide support to emergency department nurses by conducting trauma training and establishing mental health promotion strategies. In addition, multicenter cross-sectional studies, cohort studies, or qualitative studies are needed to clarify the influencing factors and mechanisms of secondary traumatic stress, to promote the development of effective intervention strategies.

Disclosure statement

No potential conflict of interest was reported by the author(s).