• No study reported on the incidence of mental health or occupational stress issues among Emergency Medical Service (EMS) clinicians or telecommunicators.
• Prevalence of mental health or occupational stress issues:
  • Among telecommunicators during routine practice, the prevalence of depression is 15.5 percent, suicidal ideation is 12.4 percent, suicide plans is 5.7 percent, suicide attempts is 0.7 percent, alcohol abuse is 15.5 percent, high/extreme peritraumatic distress is 5 percent, high secondary traumatic stress is 16.3 percent, and acute stress disorder is 17 percent (low strength of evidence (SoE) for each). After critical mass incidents, the prevalence of high general stress is 39.7 percent (low SoE).
  • Among EMS clinicians during routine practice, the prevalence of suicidal ideation is 33 percent, suicide plans is 8.7 to 10.9 percent, and suicide attempts is 2.8 to 5.6 percent (moderate SoE). During routine practice as well as after critical mass incidents, the prevalence of depression, anxiety, post-traumatic stress disorder (PTSD), burnout, and stress each varies considerably (low SoE for each).
• Severity (based on mean scores) of mental health and occupational stress issues:
  • Among telecommunicators during routine practice, the mean levels of depressive symptoms and stress are mild/low to moderate and mean levels of burnout are mild to severe (moderate SoE for each). The mean levels of peritraumatic distress are moderate and secondary traumatic stress are mild (low SoE for each). After critical mass incidents, the mean levels of burnout and general stress are moderate (low SoE).
  • Among EMS clinicians during routine practice, the mean levels of depressive symptoms are minimal to mild while the mean levels of anxiety and operational and organizational job stress are mild to moderate, and the mean levels of burnout and general stress are mild to severe; secondary traumatic stress are mild; and alcohol use are of low risk (moderate SoE for each). The Suicide Behaviors Questionnaire-Revised (SBQ-R) mean score from four studies is 4.92 (95% confidence interval [CI] 2.44 to 7.39; SBQ-R ≥ 7 implies risk of suicide; moderate SoE). The mean levels of moral injury are moderate (low SoE). After critical mass incidents, the mean levels of depressive symptoms are minimal to mild and anxiety are mild to moderate (moderate SoE for each).
• Mindfulness-building interventions targeting both resistance and resilience among EMS clinicians may be associated with reduced burnout at up to 6 months of follow-up (low SoE).

Objectives. This systematic review addresses the mental health of the Emergency Medical Services (EMS) and 911 telecommunicator workforces. We addressed four Key Questions (KQs) related to the: (1) incidence, prevalence, and severity of mental health and occupational stress issues; (2) benefits and harms of interventions to promote resistance and resilience regarding these issues; (3) contextual and implementation factors of studies with effective EMS and telecommunicator workforce practices to address these issues; and (4) future research that is needed to close existing gaps regarding addressing mental health and occupational stress issues in the EMS and telecommunicator workforces.

Data sources. We searched Medline®, Embase®, Cochrane CENTRAL, PsycINFO,® and CINAHL®, journals not indexed in Medline®, ClinicalTrials.gov, Websites, and from January 2001 through October 2023. To increase applicability to the U.S. decision-making context, we restricted to studies conducted in high-income countries.

Review methods. We used DistillerSR® for screening and the Systematic Review Data Repository Plus (SRDR+) for data extraction. We assessed the risk of bias, conducted meta-analyses, and evaluated the strength of evidence (SoE) using standard methods. We registered the protocol in PROSPERO (registration number CRD42023465325).

Results. We included 170 studies (2 randomized controlled trials, 1 nonrandomized trial, 4 pre-post studies, 6 cohort studies, and 157 cross-sectional studies). KQ1: We included 163 studies. No study reported on incidence of any outcome in any population. Among telecommunicators during routine practice, the prevalence of any depression is 15.5 percent, suicidal ideation is 12.4 percent, suicide plans is 5.7 percent, suicide attempts is 0.7 percent, alcohol abuse is 15.5 percent, high/extreme peritraumatic distress is 5 percent, high secondary traumatic stress is 16.3 percent, and acute stress disorder is 17 percent (low SoE for each). Among telecommunicators after critical mass incidents, the prevalence of high general stress is 39.7 percent (low SoE). Among EMS clinicians during routine practice, the prevalence of suicidal ideation is 33 percent, suicide plans is 8.7 to 10.9 percent, and suicide attempts is 2.8 to 5.6 percent (moderate SoE). Among EMS clinicians during routine practice or after critical mass incidents, the prevalence of depression, anxiety, post-traumatic stress disorder (PTSD), burnout, and stress vary considerably (low SoE for each). Regarding severity (based on mean levels), among telecommunicators during routine practice, depressive symptoms and stress are mild/low to moderate and burnout is mild to severe (moderate SoE for each). The mean level of peritraumatic distress is moderate and secondary traumatic stress is mild (low SoE for each). Among telecommunicators after critical mass incidents, the mean levels of burnout and general stress are moderate (low SoE). Among EMS clinicians during routine practice, the mean levels of depressive symptoms are minimal to mild while mean levels of anxiety and operational and organizational job stress are mild to moderate, mean levels of general stress and burnout are mild to severe; mean levels of secondary traumatic stress are mild; and mean alcohol use is of low risk (moderate SoE for each). The Suicide Behaviors Questionnaire-Revised (SBQ-R) mean score is 4.92 (95% confidence interval [CI] 2.44, 7.39; 4 studies; SBQ-R ≥ 7 implies at risk of suicide; moderate SoE). The mean level of moral injury is moderate (low SoE). Among EMS clinicians after critical mass incidents, the mean levels of depressive symptoms are minimal to mild and for anxiety are mild to moderate (moderate SoE for each). Some modifying factors (e.g., more trauma exposure, more hours per week, more burnout, higher call volumes) may be associated with poor outcomes. KQ2: We included eight studies. Mindfulness-building interventions targeting resistance and resilience among EMS clinicians may be associated with reduced burnout at up to 6 months of follow-up (low SoE).  KQ3: We included five studies. We found no evidence regarding effective telecommunicator workforce practices to improve mental health and occupational stress issues.  KQ4: Future research should evaluate mindfulness-based interventions and various prioritized outcomes. Future studies should be randomized trials or non-randomized studies that account for important confounders. Future studies should report on characteristics of the agencies in which the study was conducted.

Conclusions. This systematic review documents the prevalence and severity of mental health and occupational stress issues in the EMS and telecommunicator workforces. Future research should evaluate the incidence of each mental health and occupational stress issue as well as the prevalence and severity of outcomes that were not adequately reported or had inconsistent results. Mindfulness-building interventions may be associated with reduced burnout among EMS clinicians. To develop and strength preventive and early therapeutic interventions, attention should be given to the modifying factors associated with poor outcomes.