Posttraumatic stress symptoms and health-related quality of life: a two year follow up study of injury treated at the emergency department
Posttraumatic stress symptoms and health-related quality of life: a two year follow up study of injury treated at the emergency department
Juanita A Haagsma 0
Suzanne Polinder 0
Miranda Olff 2
Hidde Toet 1
Gouke J Bonsel 0
Ed F van Beeck 0
0 Department of Public Health, Erasmus Medical Center, Erasmus University Rotterdam , The Netherlands
1 Consumer Safety Institute , The Netherlands
2 Center for Psychological Trauma, Department of Psychiatry, Academic Medical Center/de Meren, University of Amsterdam , The Netherlands
Background: Among injury victims relatively high prevalence rates of posttraumatic stress disorder (PTSD) have been found. PTSD is associated with functional impairments and decreased health-related quality of life (HRQoL). Previous studies that addressed the latter were restricted to injuries at the higher end of the severity spectrum. This study examined the association between PTSD symptoms and health-related quality of life (HRQoL) in a comprehensive population of injury patients of all severity levels and external causes. Methods: We conducted a self-assessment survey which included items regarding demographics of the patient, accident type, sustained injuries, EuroQol health classification system (EQ-5D) and Health Utilities Index (HUI) to measure functional outcome and HRQoL, and the Impact of Event Scale (IES) to measure PTSD symptoms. An IES-score of 35 or higher was used as indication for the presence of PTSD. The survey was completed by 1,781 injury patients two years after they were treated at the Emergency Department (ED), followed by either hospital admission or direct discharge to the home environment. Results: Symptoms indicative of PTSD were associated with more problems on all EQ-5D and HUI3 domains of functional outcome and a considerable utility loss in both hospitalized (0.23-0.24) and non-hospitalized (0.32-0.33) patients. Differences in reported problems between patients with IES scores higher or lower than 35 were largest for EQ-5D health domains pain/discomfort (82% versus 28%) and anxiety/depression (53% versus 11%) and HUI domains emotion (92% versus 33%) and pain (84% versus 38%). After adjusting for potential confounders, PTSD remained strongly associated with adverse HRQoL. Conclusions: Among patients treated at an ED posttraumatic stress symptoms indicative of PTSD were associated with a considerable decrease in HRQoL in both hospitalized and non-hospitalized patients. PTSD symptoms may therefore raise a major barrier for full recovery of injury patients of even minor levels of severity.
posttraumatic stress disorder; injury; functional outcome; quality of life
Posttraumatic stress disorder (PTSD) may result from
any event that involves an injury, or threatened or actual
death. Regarding injury victims PTSD prevalence rates
up to 37% have been found three months after the injury
. At long-term follow-up (> 1 year) PTSD prevalence
rates from 5%  to 32%  have been reported.
A substantial share of studies that investigated
prevalence rates and predictors of PTSD following injury
addressed certain injury subgroups, such as victims of
motor vehicle accidents [4-7], burn victims [8-10] or
patients who required admission to hospital or the
Intensive Care Unit [3,11-15]. Those previous studies were
mainly conducted in clinical patient populations and
were therefore restricted to accidents and injuries at the
higher end of the severity spectrum.
PTSD generally originates from cumulative exposure
to traumatic stressors, which also influence the
probability of spontaneous remission from PTSD [16,17]. The
level of traumatic stressors in the population of study
may therefore affect to a large extent the prevalence
rates found in studies on injury victims and which focus
on a single stressor.
PTSD is associated with functional impairments and
decreased health-related quality of life (HRQoL) [18,19]. In
one of the scarce studies addressing the latter, Holbrook
et al.  showed that in a subgroup of injury patients
admitted to a trauma centre PTSD has a substantial impact
on health-related quality of life. Similar results were found
among adolescents and children [21,22]. However, these
studies were again restricted to victims at the higher end of
the severity spectrum and the association between PTSD
and health-related quality of life among a comprehensive
population of injury patients has yet to be studied.
The objective of this study was to assess the association
between posttraumatic stress symptoms indicative of
PTSD and HRQoL among this comprehensive injury
A patient-follow-up study, which was previously published
, was conducted among a population-based sample of
injury patients of all severity levels. This study followed
injury patients aged 15 years and older who attended the
ED of the Dutch Injury Surveillance System (a
representative continuous registry of intentional and unintentional
injuries of 17 hospitals in the Netherlands). Surveys were
conducted at 2 months, 5 months, 9 months and two
years after initial treatment. This study was conducted
with the approval of the Ethics Committee Erasmus MC
Between 8 October 2001 and 31 December 2002 a sample
was selected of 8,564 patients aged 15 years and older who
attended the ED of the Dutch Injury Surveillance System
. The patients were treated at the ED, followed by
either hospital admission or direct discharge to the home
environment. The sample of patients consisted of victims
of traffic, home and leisure, occupational and sport
accidents. The sustained injuries varied from minor to severe
injury, single and multiple injury and hospitalized and
non-hospitalized patients. The sample of patients was
stratified, over sampling patients who were hospitalized. Each
injury patient of the selected sample received a postal
questionnaire 21/2 months after the injury and 3,167
(37%) responded. The first questionnaire was made
anonymous for privacy reasons. At 5, 9 and 24 months a
follow-up questionnaire was sent to patients that
responded to the preceding questionnaire. For these
questionnaires the patients needed to give permissions by an
informed consent form. The 5, 9 and 24 months follow-up
questionnaire were completed by respectively 2,384, 2,295
and 1,781 patients. The present study used a sample of
1,781 respondents (i.e 21% of the original sample) on the
two year post-trauma survey, which assessed both
posttraumatic stress symptoms and HRQoL . To adjust
the data for non-response, a non-response analysis was
conducted . Multivariate logistic regression analysis
was used to examine if variables age, sex, type of injury,
external cause of the injury, hospitalization and length of
stay, health status and ambulance transport were possible
determinants of non-response. The significant variables
were used to adjust for response bias by inverse probability
weighting . Additionally, the data were adjusted for
stratification of the sample of ED patients 
The follow-up questionnaire included items regarding
demographics of the patient, accident category, type of
injury, health care use and the Impact of Event Scale
(IES), which was used to assess symptoms of
posttraumatic stress indicative of PSTD . The IES consists of
15 items, which measure intrusive re-experiences of the
trauma and avoidance of trauma-related stimuli. By
combining the 15 items the total IES-score, ranging from 0
through 75, can be calculated. Wohlfarth et al. showed
that a cut-off score of 35 on the total IES-score produced
a sensitivity of .89, and a specificity of .94 against the
DSM-IV diagnostic criteria for PTSD as the gold
standard . Therefore, we assumed that an IES-score
higher than 35 (IES 35) represents symptoms of
posttraumatic stress indicative of PTSD. The Dutch
translation of the IES has been found to be valid and reliable
Additionally, the questionnaire included items to
measure functional outcome and HRQoL. HRQoL is an
index of perceived functional outcome of an illness and
disability that is anchored between 0 (worst imaginable
health state or death) and 1 (full health), thus allowing
comparison between the health status of patients with
distinct diseases. To measure HRQoL, multi-attribute
utility instruments (MAUIs) such as the Health Utility
Index (HUI) or the EQ-5D may be used [28,29]. These
instruments require the patient to report his or her
health state with a standardised generic health state
classification system, which is then converted into a health
utility score using utility weights derived from the general
population. Despite the similarities in obtaining the
health utility score, there are important variations
between the instruments regarding the health domains
included in the health classification system and the
methods applied to derive the utility weights . As a result
of these variations, the distinct instruments yield different
utilities for similar health states. To overcome omissions
in measuring HRQoL it is important to use several
instruments that have complementary health domains
Therefore, to measure functional outcome and HRQoL,
the questionnaire included the EQ-5D and the HUI mark
3 (HUI3). With the EQ-5D classification system,
respondents describe their health in three levels of severity on
the health domains mobility, self-care, usual activities,
pain/discomfort and anxiety/depression .
Subsequently, the weight of that health state is computed by a
formula that firstly yields a partial weight score for each
domain depending on the reported level and secondly
adds the utility weights (also referred to as the tariff),
which are based on preference data of the general
population of the UK .
For instance, a patient reports some problems with
walking and performing usual activities, as well as
moderate pain or discomfort (EQ-5D profile 21221). Full health
has a utility value of 1. Because the health state of the
patient deviates from the best possible health state
(EQ5D profile 11111), a fixed reduction of -.081 is applied. For
the problems with walking, performing usual activities and
moderate pain or discomfort reductions are applied of
-0.069, -0.036 and -0.123 respectively. This is results in a
utility of 0.691. The complete algorithm to calculate
EQ5D utilities is published by Dolan et al. 
The questionnaire included 19 items regarding the
presence of one or more chronic disease(s) prior to the injury
to assess comorbidity . Comorbidity is defined as the
presence of any coexisting medical conditions or disease
processes additional to the injury that the injury patients
For analysis of the data the Statistical Package for the
Social Sciences version 14.0 was used (SPSS Inc,
Chigaco, Ill). The IES-score can be calculated if all IES
items are completed. In 8% of the cases data of one of
the 15 IES items was missing. For these cases, the
missing IES item was estimated by calculating the median
value of 5 nearby points. The missing data was then
imputed by the estimated values . If more than one
of the 15 IES items was missing, data were not imputed.
Chi-square statistics (dichotomous variables) and
Student t tests (continuous variables) were used to test for
differences between injury patients with IES scores
higher or lower than 35.
Univariate logistic regression and multivariate logistic
regression analyses (enter method) were used to
determine the predictive value of patient demographics,
accident category and severity level of the sustained injuries
with regard to posttraumatic stress symptoms indicative
of PTSD (IES 35) at two-year post-trauma. To
dichotomize severity level, the injury diagnoses were
categorized into two severity classes (mild versus moderate to
severe) as previously tested by an international expert
group . The injury severity class moderate to severe
comprises injuries such a skull-brain injury,
fracture/dislocation of the vertebral column, fracture of pelvis and
hip fracture. The injury severity class mild comprises
injuries such as superficial injury, concussion and wrist
For the analysis of the association between IES 35
and HRQoL, we selected participants that filled in both
EQ-5D and HUI3. To test differences between
participants with and without PTSD regarding their responses
on each of the EQ-5D and HUI3 health domains, the
non-parametric Wilcoxon-Mann-Whitney test was
conducted. Differences regarding the mean EQ-5D and
HUI3 summary scores were tested with a one-way
ANOVA. P-values < 0.05 were considered to indicate
Stepwise multiple regression analyses (enter method)
was applied to investigate the association between
demographics (block 1), hospitalization and comorbidity (block
2) posttraumatic stress symptoms indicative of PTSD (IES
35) (block 3) and HRQoL measured with the EQ-5D
Regarding the respondents on the 24-month follow-up
questionnaire, the average age was 44.5 years old and 46%
were female. Over one half (54%) was injured due to home
and leisure accidents. The sustained injuries of all the
respondents consisted mostly of superficial injury/open
wounds (51%) and upper extremity fractures (13%). After
treatment at the ED, 9% of the respondents were admitted
to hospital. Approximately one third (31%) had one or
more pre-existing comorbid conditions. Table 1 shows the
characteristics of the injury patients, accident category and
Table 1 Characteristics of the injury patients, accident
category and hospitalization status
(n = 1781)a
Age 44.9 (sdb 23.1)
Female sex 46%
Comorbid disease 31%
Home and leisure 54%
a Weighted for stratification of the sample of injury patients
and non-response.b sd = standard deviation
Association of posttraumatic stress symptoms indicative
of PTSD (IES 35) with HRQoL
With reference to the 1,781 respondents that completed
the 24-month follow-up questionnaire, 1,585 (89%) filled
in the EQ-5D and the HUI3 and 1,380 (77.5%) filled in
EQ-5D - Table 2 shows the responses on the EQ-5D of
injury patients with IES scores higher or lower than 35.
The calculated mean EQ-5D summary score for injury
patients with IES scores 35 was 0.56, whereas for injury
patients with lower IES scores the mean EQ-5D summary
score was 0.87 (t = 112.0; p < 0.001). Respondents with
posttraumatic stress symptoms indicative of PTSD
reported significantly more problems on all five EQ-5D
health domains (p < 0.001). Differences in reported
problems between patients with IES scores higher or lower
than 35 were largest for EQ-5D health domains
pain/discomfort (82% versus 28%) and anxiety/depression (53%
When the responses of hospitalized and
non-hospitalized injury patients with IES 35 and IES < 35 are
presented separately, again patients with symptoms indicative
of PTSD (IES 35) report significantly more problems on
each of the EQ-5D health domains, resulting in a mean
EQ-5D utility loss of 0.32 for non-hospitalized patients
(t = 112.2; p < 0.001) and 0.23 for hospitalized patients
(t = 22.1; p < 0.001). Compared to the injury patients
without PTSD indications, injury patients with symptoms
indicative of PTSD (IES 35) at 24-months post-trauma also
had significantly lower mean EQ-5D utility scores at the
21/2-month (t = 105.0, p < 0.001), 5-month (t = 100.1, p <
0.001) and 9-month (t = 38.1, p < 0.001) follow-up.
Figure 1 shows the mean EQ-5D utility score of
nonhospitalized and hospitalized patients with and without
symptoms indicative of PTSD at 21/2, 5, 12 and 24
HUI3 - Table 2 also shows the responses on the HUI3
domains reported by injury patients with IES-scores
higher or lower than 35. For patients with IES 35 the
calculated mean HUI3 summary score was 0.51 and for
patients with lower IES-scores 0.83 (t = 81.1; p < 0.001).
Respondents with posttraumatic stress symptoms
indicative of PTSD (IES 35) reported significantly more
problems on all HUI3 health domains, except hearing where
a reverse association was found (p < 0.001). Differences
in reported problems between patients with IES 35 and
IES < 35 were largest for the HUI3 health domains
emotion (92% versus 33%) and pain (84% versus 38%).
Analysing the responses of non-hospitalized and hospitalized
patients with and without PTSD indications (IES 35)
separately shows that hospitalized patients with
symptoms indicative of PTSD (IES 35) reported most
problems. Non-hospitalized patients with lower IES-scores
reported least problems on the HUI3 health domains.
Symptoms indicative of PTSD (IES 35) were associated
with a mean utility loss of 0.33 in non-hospitalized
patients (t = 80.8; t < 0.001) and 0.24 in hospitalized
patients (t = 15.9; t = 0.001)
The models tested to predict HRQoL measured with
EQ-5D and HUI3 were both statistically significant
Table 2 Mean utility scores and percentage of reported problems on the EQ-5D and HUI3 health domains of the
respondents without and with posttraumatic stress symptoms (PTSS) indicative of posttraumatic stress disorder
No posttraumatic stress symptoms
(IES-score < 35; n = 1708)
2 5 12 24
Time interval (months)
Figure 1 Mean EQ-5D utility score of non-hospitalized and
hospitalized patients. with and without symptoms indicative of
post-traumatic stress disorder (PTSS) at 21/2, 5, 12 and 24 month
(EQ-5D: F = 80.27, p < 0.001; HUI3: F = 118.55, p < 0.001).
Table 3 shows that posttraumatic stress symptoms
indicative of PTSD (IES 35) are associated with decreased
HRQoL, even after controlling for possible confounders.
Posttraumatic stress symptoms indicative of PTSD were
associated with more problems on almost all domains of
functional outcome and a considerable decrease of
HRQoL in both non-hospitalized and hospitalized injury
patients two years post-injury.
Previous studies on PTSD and HRQoL were
conducted in clinical patient populations and were therefore
restricted to accidents and injuries at the higher end of
the severity spectrum [20-22]. This study was not
restricted to particular injury subgroups, such as
Analysis based on stepwise multivariate regression analysis with
demographics (age, sex) as block 1; comorbidity, hospitalization and severity
level of the injury as step 2, and posttraumatic stress symptoms (PTSS)
indicative of posttraumatic stress disorder as step 3.
adolescent victims or victims with severe injuries
[4,8,11,12,20]. The high variety in injuries included in
this study and the relatively large sample size allowed
examination of the association of a number of injury
characteristics and posttraumatic stress symptoms
indicative of PTSD.
We found that injury patients with posttraumatic
stress symptoms indicative of PTSD reported
significantly more problems on all EQ-5D and almost all
HUI3 health domains. A study that investigated HRQoL
with EQ-5D among patients with PTSD following
cardiac arrest reported similar findings . Among
adolescent victims PTSD was associated with impairments in
Role/Social Behavioral, Role/Social Physical, Bodily Pain,
General Behavior, Mental Health, and General Health
Perceptions subscales of the 87-item Child Health
Questionnaire . The resulting EQ-5D and HUI3 utility
scores of injury patients with PTSD found in the current
study are approximately in the range of the utility scores
that Holbrook et al. derived with the multi-attribute
utility instrument Quality of Well-being scale (QWB) (0.58
- 0.62) . Although the HUI3 instrument yielded
significantly lower health utility scores compared to the
EQ-5D, which accords with results of other studies
[40-42], both HUI3 and EQ-5D showed that PTSD was
associated with a mean utility loss of 0.17 - 0.25. This
concurs with the utility loss of anxiety disorders social
phobia, generalized anxiety disorder and agoraphobia
It should be noted that Holbrook et al. focused on
injury patients admitted to a trauma centre with a length
of stay of more than 24 hours and patients injured due to
unintentional and intentional injury, whereas the current
study included all admitted injury patients to general and
university hospitals who were injured due to
unintentional injury. Moreover, Holbrook et al. used an
IESscore greater than 24 to identify patients with PTSD,
whereas in the current study a cut off of 35 was used.
Evidence from studies on this matter suggests that to
avoid overestimation of the number of cases with PTSD,
an IES-score of greater than 35 is more appropriate
[26,44]. Using the DSM-IV as the diagnostic criteria for
PTSD, a cut-off score of 35 produced sensitivity of .89,
specificity of .94 . With a cut-off point of 24, the
sensitivity is 0.91 and the specificity 0.46 . To avoid over
diagnosing of PTSD in a comprehensive population with
a relative low PTSD prevalence, it is important to use a
high IES cut-off score that incurs a high specificity.
Nonetheless, an important shortcoming of this study
was that existence of PTSD symptoms was measured
with the IES rather than Clinician-Administered PTSD
Scale for DSM-IV (CAPS). The IES is a self-report
questionnaire that measures only two of the three main PTSD
symptoms, namely intrusion and avoidance. It is not a
diagnostic tool, i.e., it is not designed to diagnose mental
disorders according to the DSM-IV (the fourth edition of
the diagnostic and statistical manual for psychiatric
disorders). Consequently, cases that in the current study
were identified as having PTSD symptoms might not
meet the DSM-IV criteria of clinical PTSD, and inversely.
Due to differences in assessment of PTSD symptoms it is
difficult to compare the results found in this study to
previous studies on PTSD and health-related quality of life
Both hospitalized and non-hospitalized injury patients
with symptoms indicative of PTSD at 24 months
postinjury reported a decrease in health status after 9
months, which may indicate that the sample is starting
a deterioration process. On the other hand, patients
might have overestimated their 9-month health status
(and possibly also their 5-month health status), because
their frame of reference has changed as a result of a
temporary decrease in health status after the injury
(response shift) [46,47]. However, without information
on PTSD status at previous measure points, the reasons
for the reductions in HRQoL at 24-months post-injury
can only be speculated about.
Functional consequences of injury, both temporary and
permanent, show large variations dependent on the
injury location and injury type. In the current study we
used the European injury classification EUROCOST .
This classification is compatible with the International
Statistical Classification of Diseases, Injuries and Causes
of Death - Ninth revision (ICD-9) classification system
an consists of 39 injury groups that are homogeneous in
terms of healthcare use, disability, as well as treatment
and prognosis. In terms of anatomical classification the
EUROCOST classification is simple compared to the
ICD, which provides very detailed information on injury
diagnoses by location and type of injury.
A second limitation of this study was the low response
rate of the follow-up questionnaires . The 24-month
follow-up questionnaire, which included the IES, was
send only to those patients who responded to the
preceding three follow-up questionnaires send at 21/2, 5 and 9
months. This meant that only 21% of the patients of the
initial sample selected for the follow-up study filled in
the 24-month follow-up questionnaire. However, the
data were adjusted for non-response and possible
response bias, because the PTSD prevalence rates were
calculated using data that were weighted with respect to
the original sample size and composition by inverse
probability weighting. For some aspects, such as the
severity of sustained injuries, the adjustments of
nonresponse could be improved, since injury severity scores
were not available.
Evidence suggested that patients with very severe
health problems are less likely to respond to a survey
. Differential underreporting by level of severity
cannot be excluded, since we found a larger proportion of
hospitalized patients among those with PTSD at 2 years
post-injury. This could partly be caused by missing a
larger share of the more severely injured hospitalized
patients among those without PTSD (e.g. comatose
patients). This may have led to a slight overestimation
of the utility losses due to PTSD. However, severely
injured patients are only a minor part of the total
sample and PTSD remained significantly associated to
adverse HRQoL, even after adjustment for confounders
including hospitalization status.
In the current study PTSD is measured at 24 months
follow-up only. A longitudinal study on PTSD and
HRQoL among injury patients might elucidate any
causal relationship between PTSD and subsequent reduced
HRQoL. Furthermore, the influence of earlier HRQoL
on PTSD remains to be investigated.
We conclude that among patients admitted to an ED
due to injuries of all causes and severity levels
posttraumatic stress symptoms indicative of PTSD are associated
with decreased HRQoL even after correction for
possible confounders such as comorbidity. PTSD seems a
major barrier for full recovery of injury patients of even
minor levels of severity, and the development and
evaluation of ED based policies for its early diagnosis and
treatment should therefore be stimulated.
ED: emergency department; HRQoL: health-related quality of life; HUI: health
utilities index; IES: impact of event scale; MAUI: multi-attribute utility
instrument; PTSD: posttraumatic stress disorder.
Authors contribution information
JAH executed the statistical analysis and drafted the manuscript. SP
participated in the design of study, assisted with the statistical analysis and
drafting of the manuscript. HT participated in the design of the study and
data collection. MO participated in the design of study and drafting of the
manuscript. GJB participated in the design of study and drafting of the
manuscript. EFvB supervised, participated in the design of study and drafting
of the manuscript. All authors read and approved the final manuscript.
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