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Trauma exposure and symptoms of post-traumatic stress disorder in emergency medical services personnel in Hawaii
  1. Shalini Mishra1,
  2. Deborah Goebert1,
  3. Elizabeth Char2,
  4. Patricia Dukes2,
  5. Iqbal Ahmed1
  1. 1University of Hawaii, John A Burns School of Medicine, Department of Psychiatry, Honolulu, Hawaii, USA
  2. 2City and County of Honolulu, Department of Emergency Services, Honolulu, Hawaii, USA
  1. Correspondence to Deborah Goebert, Department of Psychiatry, University of Hawaii, John A. Burns School of Medicine, 1356 Lusitana Street 4th Floor, Honolulu, Hawaii 96813, USA; goebertd{at}


Background Exposure to traumatic stressors is potentially an integral part of the job for emergency medical services (EMS) personnel, placing them at risk for psychological distress and mental health problems.

Study objective The prevalence of post-traumatic stress disorder (PTSD) and post-traumatic stress symptoms was examined in a sample of EMS personnel in a multiethnic locality in Hawaii. Commonly encountered traumatic incidents at work were also assessed.

Methods The PTSD Check List-Civilian version was sent to 220 EMS personnel. The survey included questions on demographics, traumatic incidents at work, general stressors, coping methods and post-traumatic stress symptoms.

Results 105 surveys were returned (48% response rate); 4% of respondents met clinical diagnostic criteria for PTSD, 1% met subclinical criteria for PTSD, 83% reported experiencing some symptoms but no PTSD and 12% had no symptoms. However, few had received treatment for these symptoms. Serious injury or death of a co-worker along with incidents involving children were considered very stressful. General work conditions also contributed to the overall stress levels. Most common coping strategies reported were positive reinterpretation (63%), seeking family and social support (59%) and awareness and venting of emotions (46%), with significant differences by ethnicity.

Conclusion EMS personnel are at high risk of experiencing post-traumatic stress symptoms. Early identification and treatment of potential stressors, psychiatric and medical problems is warranted and necessitates ongoing assessment and employee assistance programmes at the minimum.

  • Mental health
  • emergency ambulance services
  • staff support
  • psychology
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The stress that results from exposure to traumatic events can precipitate a spectrum of psychoemotional and psychopathological outcomes such as post-traumatic stress disorder (PTSD), depression, anxiety disorders and co-occurring substance abuse. PTSD is a psychiatric disorder that results from the experience or witnessing of traumatic or life-threatening events. The most frequently experienced traumas are witnessing someone being badly injured or killed, being involved in a fire, flood or natural disaster, and being involved in a life-threatening accident. The lifetime prevalence of PTSD among adults ranges from 1% to 8%, depending on the country and methodology used, with women more likely to be affected than men.1–3 Many of those who experience a traumatic incident may exhibit symptoms but may not meet the full criteria for PTSD as defined by the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-R). Subclinical PTSD can be defined as satisfying criterion B (re-experiencing) and either criterion C (avoidance) or criterion D (hyperarousal), but not both.2 Rates of subclinical PTSD have ranged from 15% to 40%.4–6 Subclinical PTSD has been associated with significant impairment in vocational and social functioning as well as higher rates of depression and poorer physical health.4 7

Despite being identified as a high-stress occupational group, few studies have examined the prevalence of mental health issues among emergency medical services (EMS) personnel.8 Previous studies have identified a prevalence of PTSD as low as 6% and as high as 22% in this group.9 10 The most common symptoms reported were re-experiencing, avoidance and hyperarousal. Berger and colleagues suggested that this was due to other risk and protective factors.6 In addition to event-related variables, empirical research has suggested risk factors that the individual brings to his or her work, such as age, background of the person and personality characteristics.11 There have been reports of the influence of earlier psychiatric history as a risk factor.12 One of the primary factors related to decreased distress and increased resilience in emergency service and relief personnel is social support.10

Certain ethnic groups have been found to be more at risk for development of PTSD symptoms. For example, in a study of urban police officers, more PTSD symptoms were reported among Hispanic-American officers.13 Sociocultural factors unique to Hispanic-Americans, such as reporting style and culture-bound idioms of distress, may explain the increased PTSD levels observed in this group.14 ‘Ataque de nervios’ is a culture-bound expression of distress seen in Hispanic people. ‘Ataque’ comprises symptoms of anger, agitation and altered level of consciousness along with hallucinations sometimes which are similar to hyperarousal and dissociative symptoms of PTSD. While African Americans, Asian Americans and native Americans tended to report having experienced fewer traumatic events than European Americans and Latinos, they were all more likely to develop PTSD after experiencing a traumatic event.15 However, lifetime prevalence rates for PTSD in Vietnam veterans were higher among all ethnic minority samples except Japanese Americans when compared with European Americans.16 This study examines the prevalence of PTSD and post-traumatic stress symptoms among an ethnically diverse group of EMS personnel.



Two hundred and twenty EMS personnel working for the City and County of Honolulu were eligible for the study. This represents the total number of the city's EMS personnel. This sample included 80 basic emergency medical technicians and 140 paramedics. The City and County of Honolulu encompasses the entire island of Oahu and includes metropolitan, suburban and rural areas. Serving a population of approximately one million, EMS personnel respond to more than 66 000 calls each year for medical emergencies and traumatic injuries.


Potential participants received a letter distributed at the EMS main office in May 2007 inviting them to complete a short online survey related to PTSD. Two reminders were sent out and the survey was left open online through July 2007. The letter served as both an invitation to participate and as the informed consent; a participant's completion of the form was taken as consent to participate. In addition, a copy of the survey, referral list for PTSD information and treatment and self-addressed return envelopes were included. Participants had the option of completing the survey either on paper or online. The survey took about 15 min to complete and was anonymous. In appreciation of their time, participants received a US $10 gift card.


The survey included a short PTSD-related questionnaire and the PTSD Checklist-Civilian version (PCL-C). The short PTSD-related questionnaire addressed criteria A (trauma exposure) and F (impairment) of DSM-IV-R diagnosis of PTSD, demographic variables, types of traumatic events encountered most commonly at work, general work conditions which contribute to overall stress, coping methods and if treatment was sought. Sources of stress and coping strategy questions in the questionnaire were adapted from Clohessy and Ehlers.9

The PCL-C consists of 17 questions that correspond to DSM- IV-R criteria for PTSD.17 18 Respondents are asked how often they have been bothered by each symptom in the past month on a 5-point severity scale, (1=not at all and 5=extremely). Responses 3–5 were considered symptomatic and anything below was considered non-symptomatic. The questionnaire addressed criteria A (trauma exposure) and F (impairment) of DSM-IV-R diagnosis of PTSD as these are not taken into consideration in the PCL-C.

The information from the survey was used to categorise participants as having (1) no symptoms; (2) non-clinical symptom levels; (3) subclinical PTSD; and (4) meeting PTSD criteria. To meet PTSD criteria the participants had to have exposure to trauma (criterion A) and also had to endorse at least one re-experiencing item (criterion B); endorse at least three avoidant items (criterion C); endorse at least two hyperarousal items (criterion D); and had impairment (criterion F).19 Subclinical PTSD was defined as satisfying criteria A, B and F, and either criterion C or criterion D but not both.2


Participation rate

The survey was distributed to all EMS personnel (n=220); 105 surveys were returned, giving a response rate of 48%. Those who did not complete the PCL-C were excluded from the analyses, resulting in a sample size of 101 respondents (45% completion rate).

Demographic characteristics of EMS personnel

The final sample of 101 participants included 57% men and 43% women; 26% of respondents identified themselves as Caucasian, 26% as Japanese, 14% as Hawaiian/part-Hawaiian, 19% as mixed ethnicity (more than one), 12% as other and 2% refused to identify their ethnicity. Thirty-seven per cent were aged 18–35 years, 54% were aged 35–54 years and 8% were >55 years of age. Forty-six per cent of respondents were married, 7% were living with a partner, 35% were single and 12% were divorced. The length of time that respondents had worked in EMS ranged from 2 months to 36 years, with a median of 10 years. The respondents generally resembled all EMS employees in terms of their demographic characteristics.

Sources of stress

Table 1 shows the respondents' mean ratings for potential stressors at work. Serious injury or death of a co-worker and incidents involving children were considered the most stressful. Dealing with patients with mental health problems, patients with burns and relatives of patients were considered somewhat stressful. Dealing with suicidal patients as well as death pronouncements or dealing with dead-on-arrival cases were the least stressful. General work conditions also contributed to the overall stress levels. Conflicts between work demands and home life as well as shift work were considered somewhat stressful but dealing with frequent user calls was not very stressful.

Table 1

Mean ratings of stressors

PTSD/Subclinical PTSD

Four per cent of respondents met clinical diagnostic criteria for PTSD, 1% met criteria for subclinical PTSD, 83% reported experiencing some of the PTSD symptoms but did not meet criteria for PTSD or subclinical PTSD and 12% had no symptoms.

Criterion A (exposure)

Twenty-two per cent of respondents met criterion A of PTSD (table 2). Nearly three-quarters of respondents (71%) reported exposure to a traumatic event at some point during their experience in EMS, which involved actual or threatened death or serious injury or a threat to the physical integrity of self or others. Twenty-three reported intense fear, helplessness or horror at the time of experiencing such trauma. The younger age group (18–24 years) reported significantly more trauma exposure during their experience working in the EMS than the older age group; this difference was significant (p=0.016). Specific ethnic groups may have experienced more traumatic incidents than others, but the findings were not significant (χ2=10.75; df=7; p=0.150). The trend seemed to show a higher rate among Caucasians (89%) and Hawaiian/part-Hawaiians (72%) compared with Japanese EMS personnel (58%).

Table 2

Frequency of meeting post-traumatic stress disorder (PTSD) criteria among emergency medical service workers

Criterion B (re-experiencing)

Twenty-seven per cent of respondents met criterion B of PTSD which includes experiencing at least one criterion B symptom. Eighteen per cent of respondents reported repeated disturbing memories, 18% reported psychological distress upon reminder of the event, 11% reported repeated disturbing dreams of the event, 8% experienced flashbacks or reliving the event and 7% had physical reactions upon reminder of even a small aspect of the event.

Criterion C (avoidance)

Eight per cent of respondents met clinical criterion C of PTSD and 8% met subclinical criterion C of PTSD. Fourteen per cent reported avoiding thinking about the event, 10% avoided activities which reminded them of the experience, 9% had difficulty remembering the important aspect of the trauma, 13% reported loss of interest in significant activities, 18% felt distant or cut off from other people, 14% reported emotional numbness and 13% felt their future would be somehow cut short.

Criterion D (hyperarousal)

Twenty-six per cent met clinical criterion D of PTSD and 14% met subclinical criterion D of PTSD. Twenty-eight per cent reported trouble sleeping, 15% felt irritable or had anger outbursts, 14% reported difficulty concentrating, 25% felt hypervigilant or super-alert most of the time and 10% had an exaggerated startle response.

Criterion F (impairment in functioning)

Twenty-nine per cent of respondents met criterion F, indicating that the work-related stress caused difficulties at work.


Of the total 5% who met the criteria for PTSD/subclinical PTSD, only two (40%) received any sort of treatment.

Coping strategies

The coping strategies reported by participants were positive reinterpretation (63%), seeking family and social support (59%), awareness and venting of emotions (46%), use of alcohol and drugs (10%) and denial (3%). Ethnic differences were found in the use of seeking family and social support as a strategy. Japanese (73%) and native Hawaiians (71%) were more likely to use this strategy than Caucasians (46%) and those of mixed ethnicity (41%; χ2=25.14; df=12; p=0.014).


Specific symptoms from criteria B and D were commonly reported among EMS personnel including intrusive thoughts and memories, psychological distress upon reminder and hypervigilance. Several studies have shown that hyperarousal and sleep disturbances were more characteristic of PTSD than were re-experiencing and emotional numbing.20 21 While a substantial proportion of EMS personnel experienced symptoms of PTSD with a few meeting the DSM-IV-R criteria for PTSD, the overall prevalence rate of PTSD in our sample was lower than in other studies of first responders and the national average prevalence of PTSD.1 6 9 10 This could be due to several factors. One reason could be the protective effect of the local culture which is very group-orientated with a strong social network as well as the cohesiveness among the EMS programme. These factors may be worth exploring in future studies. Another reason may be lower reporting due to a number of factors.

Culture may play a role in minimising symptoms.22 23 Specific symptoms from criterion B (intrusive memories, feeling upset) and criterion D (sleep problems, irritability and hypervigilance) seem to be more common, especially among certain ethnic groups. For example, the Hawaiian/part-Hawaiian group reported experiencing more intrusive thoughts and memories, psychological distress upon reminder, sleep problems and hypervigilance than Caucasians. Mental health stigma remains a major factor in many Asian cultures.23 Although the overall rates were low and statistical significance was not met, there appears to be ethnic variation which deserves further exploration in a larger sample. Denial and avoiding talking about the symptoms could also have been a contributing factor as these are core symptoms of PTSD and people experiencing these symptoms tend not to talk about it. However, avoidance appears to be a defence strategy to the distress generated by re-experiencing the trauma rather than a primary link to the symptoms.20 21 We found ethnic differences in the use of seeking family and social support as a strategy, with Japanese American and native Hawaiians reporting this strategy more frequently. This finding is consistent with research showing lower risk and stronger social support among Japanese American and native Hawaiian veterans.24

Research has shown ethnic differences in cultural belief systems such as fatalism and familism which may result in differences in risk and help-seeking behaviours.15 Assessment must therefore take into account cultural expressions of distress. DSM-IV-R offers clinical guidance in formulating the role of culture in symptomatology as well as developing a culturally sensitive treatment approach.19

Early detection can allow for early intervention, so it is important to offer treatment to all those with clinically significant PTSD symptoms. All EMS personnel should receive information regarding the phenomenon of traumatic stress. While not universally accepted, Critical Incidence Stress Debriefing (CISD) has been reported to be effective in trauma cases.25–27 It has been the most widely applied intervention strategy for use with the emergency response service personnel who have experienced some form of critical incidence stress. Initiated after the experience of a traumatic event, CISD allows the rescuers to express their thoughts and feelings about the traumatic incident following the event. However, its extension beyond this population has been criticised.25 26 All EMS managers or other relevant personnel categories should inquire about the status of their employees' exposure to traumatic experiences and their ability to cope with their working situations. Other methods of intervention to shape organisational culture have been shown to prevent or moderate the creation of burn-out and encourage effective coping, such as the peer support or ‘Buddy’ system where professionals share their concerns and experiences with each other.10 28 Preventive measures such as seeking help from peers, Employee Assistance Programs and being able to access local mental health crisis or support programs as and when needed are highly recommended.

This study has some methodological limitations. The small sample size and moderate response rate of 48% necessitates caution in interpreting the findings. EMS personnel experiencing more PTSD symptoms may have been more likely to participate in the study because of greater interest in the topic. Conversely, they may have been hesitant to take the survey due to fear of losing their job in case of being diagnosed with a mental health condition. This is the first study to examine Asian and Pacific Islander EMS personnel. The potential ethnic and gender differences found in this study warrant a larger sample to validate our findings.

The findings suggest that EMS personnel are experiencing significant PTSD symptoms and are at risk of developing PTSD and/or impairment. Preventive measures, early identification and treatment can alleviate months of suffering from distress of traumatic events. It is imperative that emergency services develop strategies for both prevention and treatment of the significant levels of mental health problems associated with emergency work. Such interventions need not only to take into account the severity and the magnitude of the problem, but also to consider ethnocultural and age differences. Future implications from the data in this study are the need for more research on subclinical PTSD, the need to identify other potential stressors for EMS personnel and also to identify other comorbid psychiatric and medical problems in this high-risk group.


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  • Competing interests None.

  • Ethics approval This study was conducted with the approval of the University of Hawaii Committee on Human Studies (IRB).

  • Provenance and peer review Not commissioned; externally peer reviewed.

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