American Journal of Epidemiology
© The Author 2013. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of
Public Health. All rights reserved. For permissions, please e-mail: [email protected].
Vol. 179, No. 2
DOI: 10.1093/aje/kwt247
Advance Access publication:
October 31, 2013
Original Contribution
Parental Bereavement After the Death of an Offspring in a Motor Vehicle Collision:
A Population-based Study
James M. Bolton*, Wendy Au, Randy Walld, Dan Chateau, Patricia J. Martens, William D. Leslie,
Murray W. Enns, and Jitender Sareen
* Correspondence to Dr. James M. Bolton, PZ430-771 Bannatyne Avenue, Winnipeg, Manitoba, Canada R3E 3N4 (e-mail: [email protected]).
Initially submitted March 15, 2013; accepted for publication September 18, 2013.
Motor vehicle collisions (MVCs) are the leading cause of death in young people in North America. The effects of
such deaths on parents have not been systematically studied. Administrative data sets were used to identify all parents (n = 1,458) who had an offspring die in a MVC between 1996 and 2008 in the province of Manitoba, Canada.
They were matched to general population control parents who had not had offspring die from any sudden cause
during the study period. Generalized estimating equations were used to compare the rates of physician-diagnosed
mental and physical disorders, social factors, and treatment utilization in the 2 parent groups in the 2 years before
and after offspring death, with adjustment for confounding factors. The risk of depression among bereaved parents
almost tripled (adjusted prevalence ratio = 2.85, 95% confidence interval: 2.44, 3.33; P < 0.001) during the 2 years
after death of an offspring. Significant increases in the risk of anxiety disorders (adjusted prevalence ratio = 1.45,
95% confidence interval: 1.26, 1.67; P < 0.001) were also observed. When compared with nonbereaved parents,
bereaved parents had significant increases in the risks of depression (P < 0.001), anxiety disorders (P < 0.001),
marital break-up (P = 0.015), and physician visits for mental illness (P < 0.001) in the post-death period. In conclusion, parents who lose an offspring in a MVC experience considerable mental illness and marital disruption.
anxiety; bereavement; depression; motor vehicle collision
Abbreviations: ICD, International Classification of Disease; MVC, motor vehicle collision.
than 130,000 bereaved parents who had a child die in a
MVC (10). Unfortunately, little is known regarding the effects of MVC deaths on bereaved parents. The few available
studies have suggested that MVC-bereaved parents suffer
emotional consequences, including depression, grief, and
posttraumatic stress disorder, that often persist years after
the death (11–15). Significant methodological shortcomings,
however, render our understanding of MVC bereavement incomplete. Existing studies are based primarily on small convenience samples that were assessed retrospectively and
therefore were subject to both sampling and recall bias. The
assessment of mental illness is variable across studies, and it
is generally limited to depression and posttraumatic stress
disorder. A recent review of the mental consequences of bereavement caused by a sudden death revealed that the majority of existing studies have relied on self-report questionnaires
to assess mental disorders, which prevents accurate estimates
Motor vehicle collisions (MVCs) are the leading cause of
death in North America among persons 5–34 years of age (1–3).
Over 35,000 people are killed annually in traffic accidents in
the United States and Canada, with the annual cost of medical expenses and lost productivity totaling over $95 billion
(4–6). MVCs ranked as the 10th leading cause of death worldwide in 2008 (7), and they are predicted to rise to the 5th leading cause of death by 2030 (8). In response to these alarming
figures, the United Nations and World Health Organization developed the United Nations Road Safety Collaboration, which
has declared 2011–2020 as the Decade of Action for Road
Safety, with the goal of preventing 5 million road traffic deaths
by 2020 (9).
The sizable number of young lives claimed by MVCs in
turn results in a substantial number of bereaved parents left
to grieve the death of their offspring. A recent study in England and Wales estimated that in 2005, there were more
177
Am J Epidemiol. 2014;179(2):177–185
178 Bolton et al.
of mental disorder prevalence (16). The authors also noted
the lack of longitudinal studies and emphasized the need
to assess other mental disorders beyond major depression
and posttraumatic stress disorder. The impact of bereavement
on physical health has also been neglected. There have been
no population-based studies of bereavement after MVCs, and
therefore epidemiologic figures on mental disorder incidence
and other consequences are unknown. Considering these limitations in the current state of knowledge, there is a clear need
for improved study methodology to achieve a better understanding of the outcomes of bereavement after MVCs.
This contrasts with the more developed literature of bereavement related to other causes of sudden death, such as
suicide or death from acute medical illnesses. Parents bereaved from other causes of sudden death suffer considerable
adverse outcomes, including psychiatric illness and higher
mortality rates (17–19). This provides additional rationale
for clarifying the consequences of bereavement after a
MVC. The recognized negative consequences of bereavement related to sudden death, along with the concerning mortality rates of MVCs, suggest that MVC bereavement among
parents is a significant and underrecognized public health
issue. Therefore, we undertook the present study to examine
the mental, physical, and social outcomes experienced by
parents who had an offspring die in a MVC. By using a
population-based sample drawn from administrative data
with physician-generated diagnoses, this study was positioned to overcome the biases in previous work and provide
the first population prevalence estimates of a comprehensive
range of mental and physical disorders associated with bereavement after a MVC.
MATERIALS AND METHODS
who died in a MVC between the years of 1996–2008 and
who had at least 1 identifiable parent (n = 801). The study period of 1996–2008 was chosen based on the completeness of
data sets from 1996 onwards, with 2008 being the most recent
year with available data. MVCs were classified according to
pre-established definitions using International Classification
of Disease (ICD), Ninth Revision, Clinical Modification codes
(E810–E819 and E822–E825) for deaths before April 1,
2004, and ICD Tenth Revision, Canada, codes (V02–V04,
V09.0, V09.2, V12–V14, V19.0–V19.2, V19.4–V19.6, V20–
V79, V80.3–V80.5, V81.0–V81.1, V82.0–V82.1, V83–V86,
V87.0–V87.8, V88.0–V88.8, V89.0, and V89.2) after April
1, 2004 (21, 22). Mothers, fathers, stepmothers, and stepfathers
of the deceased formed the bereaved group (n = 1,458). Of
these, 177 had missing data (these parents had either died
or moved away from the province), and they were not included in subsequent comparisons, providing a final comparative sample of 1,281. The date of the MVC death of the
offspring was considered the index date that was used both
for parent-matching purposes and for defining the time periods for analysis of outcomes. Nonbereaved parents from the
general population were matched 1:1 to bereaved parents
based on the offspring’s sex, region of residence, and age
at time of death, as well the parent’s relationship to the offspring (mother, father, stepmother, and stepfather), age of
parent (±3 years), and parent’s region of residence (based
on regional health authority and neighborhood clusters) at
the index date. Nonbereaved parents were excluded from
the matching if they had had any child die within the study
period as a result of a MVC or other sudden death (ICD,
Ninth Revision, Clinical Modification codes excluded:
E800-E999; ICD, Tenth Revision, Canada codes excluded:
V01-Y98).
Data sources
Outcomes of interest
Data used in the present study came from the Population
Health Data Repository housed at the Manitoba Centre for
Health Policy in the Faculty of Medicine of the University
of Manitoba. Each permanent resident of Manitoba (n = 1.2
million) is assigned a personal health information number
that is recorded with all health contacts, including outpatient
physician visits and hospital admissions. The personal health
information number is encrypted and used to link anonymized health care data sets to provide a de-identified, longitudinal record of virtually every resident in the province. Data sets
used in our study included the Vital Statistics Registry (to
identify probands who died in MVCs), the Manitoba Health
Insurance Registry (to identify parents of deceased probands
and matched parents), hospital discharge abstracts and physician claims (to identify diagnostic outcomes), and census data
(for region of residence and income). The accuracy of these
administrative data sets is excellent (20). The study was approved by the University of Manitoba research ethics board.
Diagnosed mental disorders. ICD codes were used to
identify depression (unipolar and bipolar), anxiety disorder,
alcohol abuse or dependence, drug abuse or dependence, suicide attempts, and dementia. (The specific codes are listed in
Appendix Table 1.) A category called “any mental disorder”
was created that included individuals who met criteria for any
of the above disorders. We used disorder definitions that had
been validated in previous studies using the same data sets
(23). Disorders were based on physician-generated diagnoses
from both hospitalization abstracts and outpatient physician
contacts and were treated as dichotomous variables. Rates
of disorders within parent groups were based on parents receiving a diagnosis of the disorder of interest at least once
during the examined time period. Two time periods of interest were examined based on the date of offspring death (or
index date for nonbereaved parents): the pre-death period
(2 years before offspring death) and the bereavement period
(2 years after offspring death). Two years was chosen as the
bereavement period because of previous work that demonstrated a sustained increase in the rate of depression among
those bereaved because of a sudden death in the second
year after that death (24).
Diagnosed physical disorders. Disorders of interest included cardiovascular disease, cancer, chronic obstructive
Cohort formation
There were 2 comparison groups in this study: bereaved
parents who had a child die in a MVC and nonbereaved parent matches. To construct the former, we identified all persons
Am J Epidemiol. 2014;179(2):177–185
Bereavement After Motor Vehicle Collisions 179
pulmonary disease, hypertension, and diabetes, as well as a
similar aggregate “any physical disorder” category that included individuals with any of the above disorders. (The
ICD codes are listed in Appendix Table 1.) Disorders were
based on validated diagnostic definitions (25). Similar to
the mental disorder analyses, the various physical disorders
were treated as dichotomous variables with rates based on
physical disorder exposure in the parent group, using the
same 2-year pre- and post-death timelines.
Social factors. The social variables of interest were income and marital status. Census data provided average
household income of the enumeration area where the individual resided on the index date. Average household income was
divided into 5 quintiles, with the lowest quintile defined as
the 20% of the population with the lowest average household
income. Being in the lowest income quintile was considered
the outcome of interest, with the remaining quintiles combined as the reference group. Single marital status was the
outcome of interest and included all people not registered
as married; married persons served as the reference group.
The same 2-year pre- and post-index date time periods were
used.
Health services utilization. Outpatient physician visits
and hospitalizations for mental illness and physical illness
were the service use outcomes of interest. Rates of each measure were based on the total sum of occurrences within each
parent group for each time period of interest. Hospitalization
was based on spending 1 or more days in hospital. The same
2-year pre- and post-index date time periods were used.
Statistical analysis
Generalized estimation equation regression models using
either a negative binomial or Poisson distribution were used
to calculate the adjusted prevalence ratios for each outcome
of interest. Specifically, a negative binomial distribution
was applied to the models examining health service utilization outcomes, and a Poisson distribution was applied to
the models examining mental disorder, physical disorder,
and social factor outcomes. Generalized estimation equation
models were used to account for correlated observations over
time and among matched parents. In addition, the log of the
population was also included as an offset in the model to ensure that a relative ratio as opposed to a relative count of
events was modeled. Covariates (assessed at date of offspring
death or index date) that could potentially be entered into
each of the models included: deceased offspring being the
only offspring in the family (yes vs. no), marital status of
the parent (married vs. single), parent income level (lowest
quintile vs. other), parental status type (mother or stepmother
vs. father or stepfather), age of the offspring at index date
(≤18 years of age vs. ≥19 years of age), age of the parent
at time of offspring’s death (≤39 years of age vs. ≥40
years of age), presence of a diagnosed mental disorder (yes
vs. no), and/or presence of a diagnosed physical disorder
(yes vs. no). Covariates were included in each model based
on model fit and based on the outcome of interest. For mental
disorder outcomes, as an example, models included the above
covariates minus any diagnosed mental disorder. Two sets of
analyses were conducted. The first focused solely on the
Am J Epidemiol. 2014;179(2):177–185
cohort of bereaved parents and compared the adjusted prevalence ratios of the outcomes of interest in the 2-year postdeath period with those in the 2-year pre-death period. The
second set of analyses compared the bereaved parents with
the nonbereaved matched parents using time period (predeath vs. post-death) by parent group (bereaved vs. nonbereaved) interaction terms.
RESULTS
The characteristics of the bereaved parents and nonbereaved matched parents are presented in Table 1. Differences
between the 2 groups were observed in marital status, income
level, and the frequency of single offspring. At the time of
offspring death, bereaved parents were less likely than nonbereaved parents to be married, were more likely to have
more than 1 offspring, and had higher risk of having a low
income. The mean age of the offspring who died in MVCs
was 27 years, and roughly one quarter died before the age
of 19 years. Parents were on average 55 years of age when
their offspring died.
Results of the Poisson and negative binomial regression
analyses are presented in Table 2, which shows the adjusted
prevalence of diagnosed mental and physical disorders, social factors, and treatment utilization among bereaved parents
in the 2 years before and after the death of their offspring. The
prevalence of depression rose from 10.9% to 31.3%. This
corresponded to an almost tripling of the risk of depression
after adjustment for confounders (adjusted prevalence ratio =
2.85, 95% confidence interval: 2.44, 3.33; P < 0.001). The
adjusted prevalence ratio of anxiety disorders increased by
45% (adjusted prevalence ratio = 1.45, 95% confidence interval: 1.26, 1.67; P < 0.001). Increases in the risk of physical
disorders were also observed, specifically for cancer and hypertension. Parents were more likely to be single after offspring death than they were in the 2 years before the death
(adjusted prevalence ratio = 1.15, 95% confidence interval:
1.10, 1.21; P < 0.001). Physician visits for mental illness increased considerably in the 2 years after offspring death.
The comparison between bereaved and nonbereaved
matched parents on health and social outcomes is presented
in Table 3. Before offspring death, bereaved parents and nonbereaved parents showed no significant differences in the adjusted prevalence ratios of diagnosed mental disorders. In the
2-year period after the index date, bereaved parents had
higher adjusted risks of depression, anxiety disorders, and
any mental disorder when compared with nonbereaved parents, as reflected in the significant interaction terms for time
period by parent group (all P < 0.001). There were also greater
increases in the risks of both marital break-up (P = 0.015) and
outpatient physician mental illness visits (P < 0.001) among
bereaved parents between the pre- and post-death periods.
DISCUSSION
To our knowledge, this is the first population-based study
to specifically examine bereavement after death in a MVC.
When compared with nonbereaved parents, bereaved parents
had concerning increases in the risks of psychiatric disorders
and marital break-up in the 2 years after the death of their
180 Bolton et al.
Table 1. Characteristics of Bereaved and Nonbereaved Parents in the Study, Manitoba, Canada, 1996–2008
Characteristic
Parents With
Offspring Who Died
in a MVC (n = 1,458)
No.
Nonbereaved
Parent
Controls
(n = 1,458)
%
No.
%
χ2
Relation of parent to deceased offspring
0.00
Father
572
39.2
572
39.2
Mother
770
52.8
770
52.8
Stepfather
95
6.5
95
6.5
Stepmother
21
1.4
21
1.4
7.97a*
Marital status at time of offspring’s death
Married
875
60.0
921
63.2
Single
406
27.9
537
36.8
Unknown
177
12.1b
0
0.0
90
a
11.2
164
18.4
711
88.8
726
81.6
Number of offspring
Index offspring only
>1 offspring in the family
Age of offspring at death, years
17.08**
c
26.9 (12.7)d
N/A
≤18
210
26.2b
N/A
N/A
≥19
591
73.8
N/A
N/A
Age of parent at time of offspring’s death, years
d
55.1 (14.7)
NA
≤39
168
11.5
N/A
N/A
≥40
1,290
88.5
N/A
N/A
17.60e*
Quintile of parental income at time of
offspring’s death
Lowest
336
23.0
303
Second lowest
276
18.9
288
20.8
19.8
Middle
236
16.2
308
21.1
Second highest
240
16.5
288
19.8
Highest
193
13.2
271
18.6
Unknown
177
12.1b
0
0.0
Abbreviations: MVC, motor vehicle collision; N/A, not applicable.
* P < 0.01; **P < 0.001.
a
The denominator was 801 unique offspring deaths.
b
At the time of their offspring’s death, these parents had either died or moved out of the province; thus, their marital
status and income were unknown.
c
The denominator was 890 unique offspring deaths.
d
Values are expressed as mean (standard deviation).
e
Parents with unknown marital status or income were not included in the χ2 comparison.
offspring. These findings underscore the vulnerability of this
group and emphasize the need for targeted support and treatment services geared to grieving parents. With these recognized negative consequences and in consideration of the
fact that MVCs are the leading cause of death of young people in the North America, thereby giving rise to a large number of bereaved parents, MVC bereavement clearly represents
a considerable public health concern that to date has received
less attention than bereavement related to other causes of death.
In the 2 years after the MVC death of their offspring, parents had dramatic rises in their risks of diagnosed depression
and anxiety disorders. Before the death, their risk of depression was no different than that of matched nonbereaved
parents. After the death, the risk of depression among bereaved parents almost tripled. Interaction analyses revealed
this increase to be statistically significant when compared
with nonbereaved parents over the same time period, even
after adjustment for confounding factors. These findings corroborate earlier smaller studies that showed negative mental
health outcomes among parents bereaved by MVCs (12–14,
26). Bereavement related to other causes of sudden death, including suicide and myocardial infarction, have recognized
adverse mental health sequelae, including depression, suicide, and increased all-cause mortality rates (19, 24, 27). Different bereaved relatives, such as children who lose a parent,
have also been shown to be at increased risk of depression
Am J Epidemiol. 2014;179(2):177–185
Bereavement After Motor Vehicle Collisions 181
Table 2. Mental and Physical Disorders, Social Factors, and Treatment Utilization Among Bereaved Parents
(n = 1,281) Before and After the Death of Their Offspring in a Motor Vehicle Collision, Manitoba, Canada, 1996–2008
Outcome
2-Year
Prevalence
Before Death
(n = 1,281)
No.
%
2-Year
Prevalence After
Death (n = 1,281)
No.
Adjusted
Prevalence
Ratioa
95%
Confidence
Interval
%
Mental disorders
Depression
140
10.9
401
31.3
2.85
2.44, 3.33***
Anxiety disorder
192
15.0
281
21.9
1.45
1.26, 1.67***
Alcohol use disorder
26
2.0
22
1.72
0.78
0.51, 1.20
Drug use disorder
46
3.6
34
2.7
0.72
0.49, 1.07
0.79, 2.49
Dementia
10
Suicide attempt
—b
Any mental disorder
315
0.8
—b
24.6
14
—b
550
1.1
1.40
—b
—b
—b
42.9
1.73
1.57, 1.91***
Physical disorders
Cardiovascular disease
78
6.1
93
7.3
1.18
0.97, 1.44
Cancer
52
4.1
75
5.9
1.42
1.11, 1.81**
COPD
57
4.5
51
4.0
0.90
0.70, 1.15
Hypertension
273
21.3
304
23.7
1.11
1.01, 1.22*
Diabetes
160
12.5
166
13.0
1.04
0.93, 1.15
Any physical disorder
442
34.5
491
38.3
1.11
1.04, 1.18**
Low income
358
28.0
342
26.7
0.95
0.88, 1.02
Single marital status
376
29.4
433
33.8
1.15
1.10, 1.21***
Social factors
Treatment utilizationc
Physician visit for mental illness
1,111
0.87
2,621
2.05
2.29
1.88, 2.79***
Physician visit for physical illness
2,952
2.30
3,211
2.51
1.15
0.99, 1.33
Hospitalization for mental illness
83
0.06
60
0.05
0.75
0.44, 1.27
Hospitalization for physical illness
248
0.19
326
0.25
1.28
0.95, 1.74
Abbreviation: COPD, chronic obstructive pulmonary disease.
* P < 0.05; **P < 0.01; ***P < 0.001.
a
Adjusted prevalence ratio in the 2 years after death compared with the 2 years before death. The model
covariates were deceased offspring was the only offspring in the family, parental status (mother vs. father), marital
status, low income, any mental disorder, any physical disorder, age of offspring at time of death, and age of parent
at time of offspring’s death. Covariates were assessed at time of offspring death and entered based on outcome of
interest and model fit. For mental disorder outcomes, models excluded any mental disorder as a covariate. For
physical disorder outcomes, models excluded any physical disorder as a covariate.
b
Suppressed because there were few subjects in this category (<6).
c
Treatment utilization variables were measured as a summarized count of treatment contacts, with a mean of less
than 6 physician visits or hospitalizations per person.
(24). These previous studies therefore demonstrate that certain mental disorder consequences are likely common to bereavement in general and not unique to parents or MVC
bereavement. Nevertheless, the findings from the present
study show that bereavement after a MVC death is associated
with considerable deleterious mental health issues, suggesting that health care providers should consider the potential
psychiatric needs of parents after the death of their offspring.
Findings from this study have important implications for
the mental health service provision for bereaved persons. In
addition to demonstrating a risk for psychiatric disorders
within 2 years, this study provides the first population-based
prevalence rates of diagnosed mental disorders among parents
Am J Epidemiol. 2014;179(2):177–185
who had a child die in a MVC. Within 2 years after the death of
their offspring, almost one third (31%) of parents were diagnosed with depression, 22% were diagnosed with anxiety,
and almost half (43%) had at least 1 mental disorder. These
rates were substantially higher when compared with both nonbereaved parents and the parents themselves before the death.
Bereaved parents had twice the rate of contact with physicians
for mental illness compared with nonbereaved parents. Interestingly, despite the increased rate of outpatient visits, there
was no change in rates of hospitalization. These preliminary
findings, however, require further study before definitive conclusions can be made regarding the treatment needs of people
bereaved by MVC deaths. There have been no studies that
182 Bolton et al.
Table 3. Pre-Death and Post-Death Comparisons of Bereaved Parents Whose Offspring Died in a Motor Vehicle Collision (n = 1,281) and
Nonbereaved Matched Parent Controls (n = 1,281), Manitoba, Canada, 1996–2008
2 Years Before Death
Outcome
Adjusted Prevalence
Ratioa
95% Confidence
Interval
P for
Interaction
2 Years After Death
Adjusted Prevalence
Ratioa
95% Confidence
Interval
Mental disorders
Depression
0.92
0.74, 1.14
<0.001
2.77
2.32, 3.30***
Anxiety disorder
1.11
0.92, 1.33
<0.001
1.65
1.39, 1.96***
Alcohol use disorder
1.76
0.91, 3.44
NS
1.17
0.61, 2.25
Drug use disorder
1.29
0.82, 2.03
NS
0.78
0.49, 1.24
Dementia
0.94
0.39, 2.24
NS
0.94
0.45, 1.95
Suicide attemptb
0.80
0.16, 3.87
NS
1.75
0.33, 9.31
Any mental disorder
1.07
0.93, 1.22
<0.001
1.79
1.59, 2.01***
Physical disorders
Cardiovascular disease
1.17
0.87, 1.58
NS
0.96
0.74, 1.25
Cancer
0.80
0.57, 1.14
NS
0.87
0.64, 1.16
COPD
1.26
0.87, 1.81
NS
0.92
0.63, 1.35
Hypertension
0.87
0.76, 0.99
NS
0.85
0.75, 0.96**
Diabetes
1.19
0.96, 1.47
NS
1.04
0.85, 1.28
Any physical disorder
0.99
0.90, 1.09
NS
0.93
0.85, 1.01
Low income
1.34
1.18, 1.52***
NS
1.46
1.28, 1.67***
Single marital status
1.04
0.99, 1.09
0.015
1.11
1.06, 1.17***
Physician visit for mental
illness
0.86
0.62, 1.21
<0.001
2.02
1.53, 2.67***
Physician visit for physical
illness
1.00
0.84, 1.19
NS
0.96
0.81, 1.13
Hospitalization for mental
illness
1.27
0.65, 2.50
NS
1.07
0.60, 1.90
Hospitalization for physical
illness
1.03
0.69, 1.53
NS
1.06
0.74, 1.52
Social factors
Treatment utilization
Abbreviations: COPD, chronic obstructive pulmonary disease; NS, not significant.
* P < 0.05; **P < 0.01; ***P < 0.001.
a
Adjusted prevalence ratio among bereaved parents whose offspring died in a motor vehicle collision compared with nonbereaved parent
controls within each time period. The model covariates were deceased offspring was the only offspring in the family, parental status (mother vs.
father), marital status, low income, any mental disorder, any physical disorder, age of offspring at time of death, and age of parent at time of offspring’s death. Covariates were assessed at time of offspring death and entered based on outcome of interest and model fit. For mental disorder
outcomes, models excluded any mental disorder as a covariate. For physical disorder outcomes, models excluded any physical disorder as a
covariate.
b
Relative rate based on summarized count of suicide attempts, as the dichotomous measure could not be modeled.
have investigated the perceived need for care and health service use profile of people bereaved by MVC deaths. Other
causes of sudden death, such as suicide, have shown that
88% of bereaved relatives perceive a need for treatment,
with care access rates ranging from 55% to 60% (28, 29).
Such rates reinforce the need to strategize health care delivery
for this population and underscore the sizable discrepancy
between treatment needs and care received. Successful care
delivery is additionally compromised by studies showing
that suddenly bereaved persons are not routinely offered treatment, that physicians are often not prepared to deal with the
consequences of bereavement, and that only a minority of
physicians feel satisfied with the care they have provided
(30–32). Further complicating the issue is our finding that
the majority of offspring who died were 19 years of age or
older; when the parent is no longer the guardian, treatment
approaches that involve parents may be less likely to be considered, and they may be less likely to be screened for loss.
More information is needed regarding the needs of people bereaved by MVC deaths, both to guide health care delivery and to
determine whether existing treatment modalities are sufficient
or whether other approaches, such as outreach, are required.
There are important limitations to consider in the interpretation of these results. The first relates to the specification of
parents. Identification of fathers is dependent on the registration of marriages within the provincial insurance registry.
Am J Epidemiol. 2014;179(2):177–185
Bereavement After Motor Vehicle Collisions 183
Therefore, a minority proportion of fathers were not included
in these analyses, and it is possible that these fathers differed
on the outcomes examined. A second limitation relates to the
nonbereaved parent cohort. Although parents were excluded
as matches if they had an offspring die by a sudden cause, it is
possible that they had an offspring die by another cause or
that they were bereaved by the death of another relative or
close friend. However, these possibilities are presumably
equally likely in the bereaved parent cohort. A third limitation is that receiving mental and physical disorder diagnoses
depend on a person seeking treatment. Given the findings that
showed a divergence between treatment needs and service
use among bereaved persons, it is likely that the rates observed in this study are an underrepresentation of the true
prevalence rates in the general population. Methodologies
that overcome this limitation, such as epidemiologic surveys,
could provide more accurate rates for the prevalence of disorders (treated and untreated) among bereaved parents. A fourth
limitation is that this study was restricted to outcomes available in administrative data. It was not possible to examine
factors such as social support, level of education, posttraumatic stress disorder, and complicated grief, among others,
that serve as both important outcomes and potential confounders. Nevertheless, claims data have several strengths,
including the lack of recall bias, physician-based diagnoses,
no loss in follow-up, and a population-based approach rather
than a clinical setting sample. A final limitation is that this
study was conducted in a population with universal access
to free health care, and therefore these results may not generalize to uninsured populations.
In conclusion, the present study provides the first investigation of bereavement in people who had a child die in a
MVC in a population-based sample. By examining all MVC
deaths over a 13-year interval, using validated physicianbased diagnoses, examining a diverse range of health outcomes, and using a matched nonbereaved parent group, this
study provides findings that extend our understanding of the
consequences of bereavement after a MVC-related death.
Several novel findings were observed, including considerable
increases in mental disorders and treatment-seeking after the
death of an offspring. Bereaved parents were more likely to
separate or divorce than were nonbereaved parents, further
contributing to the hardship endured by the family after the
death of the offspring. These findings underline MVC bereavement as a period of concerning vulnerability for parents.
With MVCs being the leading cause of death among the
young and given the resulting high numbers of bereaved parents, this study emphasizes the need for clinical attention and
further exploration of the consequences experienced by parents who lose an offspring in a MVC.
ACKNOWLEDGMENTS
Author affiliations: Department of Psychiatry, University
of Manitoba, Winnipeg, Manitoba, Canada (James M.
Bolton, Murray W. Enns, Jitender Sareen); Department of
Psychology, University of Manitoba, Winnipeg, Manitoba,
Canada (James M. Bolton, Murray W. Enns, Jitender Sareen);
Am J Epidemiol. 2014;179(2):177–185
Manitoba Centre for Health Policy, Winnipeg, Manitoba,
Canada (James M. Bolton, Wendy Au, Randy Walld, Dan
Chateau, Patricia J. Martens); Department of Community
Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada (James M. Bolton, Dan Chateau, Patricia
J. Martens, Murray W. Enns, Jitender Sareen); and Department of Internal Medicine, University of Manitoba, Winnipeg, Manitoba, Canada (William D. Leslie).
Preparation of this article was supported by research grants
from the Canadian Institutes of Health Research (grant
102682 to James M. Bolton) and from the Manitoba Health
Research Council (James M. Bolton), a Manitoba Health Research Council Chair Award (Jitender Sareen), and a Canadian Institutes of Health Research New Investigator Award
(grant 113589 to James M. Bolton).
We thank Manitoba Health for providing data (Health Information Privacy Committee #2010/2011-19).
The results and conclusions are those of the authors, and
no official endorsement by Manitoba Health is intended or
should be inferred. The funding sources had no role in the design and conduct of the study; no role in the collection, management, analysis, and interpretation of data; and no role in
the preparation, review, and approval of the manuscript.
Conflict of interest: none declared.
REFERENCES
1. Centers for Disease Control and Prevention. Web-based Injury
Statistics Query and Reporting System. Atlanta, GA: US
Department of Health and Human Services; 2010.
2. Ramage-Morin PL. Motor Vehicle Accident Deaths, 1979 to
2004. Ottawa, Canada: Statistics Canada; 2008. (Component of
Statistics Canada Catalogue No. 82-003-X Health Reports).
(http://www.statcan.gc.ca/pub/82-003-x/2008003/article/
10648-eng.pdf ). (Accessed January 24, 2013).
3. Statistics Canada. Leading Causes of Death. Ottawa, Canada:
Statistics Canada; 2008. (http://www.statcan.gc.ca/dailyquotidien/111101/dq111101b-eng.htm). (Accessed October
12, 2012).
4. Naumann RB, Dellinger AM, Zaloshnja E, et al. Incidence and
total lifetime costs of motor vehicle-related fatal and nonfatal
injury by road user type, United States; 2005. Traffic Inj Prev.
2010;11(4):353–360.
5. Transport Canada, Ministry of Transportation. Analysis and
estimation of the social cost of motor vehicle collisions in
Ontario: Final Report. Toronto, Canada: Transport Canada;
August 2007. (http://www.tc.gc.ca/media/documents/
roadsafety/tp14800e.pdf ). (Accessed January 24, 2013).
6. Transport Canada, Ministry of Transportation. Canada Motor
Vehicle Traffic Collision Statistics: 2009. Toronto, Canada:
Transport Canada; February 2012. (http://www.tc.gc.ca/eng/
roadsafety/tp-tp3322-2009-1173.htm). (Accessed January 24,
2013).
7. World Health Organization. The top 10 causes of death.
Geneva, Switzerland: World Health Organization; 2011.
(http://www.who.int/mediacentre/factsheets/fs310/en/).
(Accessed October 5, 2012).
8. World Health Organization. Global Health Observatory
(GHO): number of road traffic deaths. Geneva, Switzerland:
World Health Organization; 2012. (http://www.who.int/gho/
road_safety/mortality/number_text/en/). (Accessed January 24,
2013).
184 Bolton et al.
9. United Nations Road Safety Collaboration. One year on,
global commitment to the Decade of Action for Road Safety
2011-2020 intensifies. Geneva, Switzerland: World Health
Organization; 2012. (http://www.who.int/roadsafety/
decade_of_action/en/). (Accessed October 5, 2012).
10. Sullivan R, Edwards P, Sloggett A, et al. Families
bereaved by road traffic crashes: linkage of mortality
records with 1971–2001 censuses. Inj Prev. 2009;15(6):
364–368.
11. Shanfield SB, Swain BJ. Death of adult children in traffic
accidents. J Nerv Ment Dis. 1984;172(9):533–538.
12. Lehman DR, Wortman CB, Williams AF. Long-term effects
of losing a spouse or child in a motor vehicle crash. J Pers
Soc Psychol. 1987;52(1):218–231.
13. Winje D. Long-term outcome of trauma in adults: the
psychological impact of a fatal bus accident. J Consult Clin
Psychol. 1996;64(5):1037–1043.
14. Spooren DJ, Henderick H, Jannes C. Survey description of
stress of parents bereaved from a child killed in a traffic
accident. A retrospective study of a victim support group.
Omega. 2000;42(2):171–185.
15. Murphy SA, Johnson LC. Bereaved parents’ outcomes 4 to 60
months after their children’s deaths by accident, suicide, or
homicide: a comparative study demonstrating differences.
Death Stud. 2003;27(1):39–61.
16. Kristensen P, Weisaeth L, Heir T. Bereavement and mental
health after sudden and violent losses: a review. Psychiatry.
2012;75(1):76–97.
17. Seguin M, Lesage A, Kiely MC. Parental bereavement after
suicide and accident: a comparative study. Suicide Life Threat
Behav. 1995;25(4):489–492.
18. Dyregrov K, Nordanger D, Dyregrov A. Predictors of
psychosocial distress after suicide, SIDS and accidents. Death
Stud. 2003;27(2):143–165.
19. Rostila M, Saarela J, Kawachi I. Mortality in parents
following the death of a child: a nationwide follow-up
study from Sweden. J Epidemiol Community Health. 2012;
66(10):927–933.
20. Roos LL, Nicol JP. A research registry: uses, development,
and accuracy. J Clin Epidemiol. 1999;52(1):39–47.
21. Manitoba Centre for Health Policy. Concept: External cause
of injury codes and categories. Winnipeg, Canada: Manitoba
Centre for Health Policy; 2010. (http://mchp-appserv.cpe.
umanitoba.ca/viewConcept.php?conceptID=1168). (Accessed
October 5, 2012).
22. Statistics Canada. Motor vehicle accident deaths–Health
Matters. Catalogue No. 82-003-XPE Health Reports 19.
Ontario, Canada: Statistics Canada; 2008.
23. Martens P, Brownell M, Au W, et al. Health Inequities in
Manitoba: Is the Socioeconomic Gap Widening or Narrowing
Over Time? Winnipeg, Canada: Manitoba Centre for Health
Policy; 2010.
24. Brent D, Melhem N, Donohoe MB, et al. The incidence and
course of depression in bereaved youth 21 months after the loss
of a parent to suicide, accident, or sudden natural death. Am
J Psychiatry. 2009;166(7):786–794.
25. Lix L, Yogendran MS, Mann J. Defining and Validating
Chronic Diseases: An Administrative Data Approach: An
Update with ICD-10-CA. Winnipeg, Canada: University of
Manitoba; 2008.
26. Kovarsky RS. Loneliness and disturbed grief: a comparison of
parents who lost a child to suicide or accidental death. Arch
Psychiatr Nurs. 1989;3(2):86–96.
27. Fosbol EL, Petersen ED, Weeke P, et al. Spousal depression,
anxiety, and suicide after myocardial infarction. Eur Heart J.
2013;34(9):649–656.
28. Dyregrov K. Assistance from local authorities versus survivors’
needs for support after suicide. Death Stud. 2002;26(8):
647–668.
29. McMenamy JM, Jordan JR, Mitchell AM. What do suicide
survivors tell us they need? Results of a pilot study. Suicide Life
Threat Behav. 2008;38(4):375–389.
30. Wisten A, Zingmark K. Supportive needs of parents confronted
with sudden cardiac death–a qualitative study. Resuscitation.
2007;74(1):68–74.
31. Nishimaki S, Higuchi R, Nakajima S, et al. Survey of
psychological support for bereaved families in Japan. Pediatr
Int. 2009;51(5):626–629.
32. Zisook S, Shear K. Grief and bereavement: what psychiatrists
need to know. World Psychiatry. 2009;8(2):67–74.
(Appendix follows)
Am J Epidemiol. 2014;179(2):177–185
Bereavement After Motor Vehicle Collisions 185
Appendix Table 1. International Classification of Diseases Codes Used in the Study, Manitoba, Canada, 1996–
2008
Disorders
ICD-9-CM
ICD-10-CA
Mental disorders
Depression (unipolar and bipolar)
296.2–296.3, 296.5, 300.4,
309, 311
F31.3–F31.5, F32, F33, F341,
F380, F381, F432, F438, F530
Anxiety
300.0, 300.2, 300.3
F40, F41.0, F41.1, F41.3, F41.8,
F41.9, F42, F431
Alcohol abuse or dependence
291, 303
F10
Drug abuse or dependence
292, 304, 305
F11–F19, F55
Suicide attempts
E950–E959
X60–X84, Y870
Dementia
290, 291.1, 291.2, 292.82, 294,
331, 797
F00-F04, F05.1, F06.5, F06.6,
F06.8, F06.9, F09, F10.7,
F11.7, F12.7, F13.7, F14.7,
F15.7, F16.7, F18.7, F19.7,
G30, G31.0, G31.1, G31.9,
G32.8, G91, G93.7, G94, R54
Cardiovascular disease
410–414
I20–I25
Cancer
140–208
C00.0–C41.9, C45.0–C97
COPD
491, 492, 494, 496
J41, J42, J43, J44, J47
Hypertension
401–405
I10–I13, I15
Diabetes
250
E10–E14
Physical disorders
Abbreviations: COPD, chronic obstructive pulmonary disease; ICD-9-CM, International Classification of Diseases,
Ninth Revision, Clinical Modification; ICD-10-CA, International Classification of Diseases, Tenth Revision, Canada.
Am J Epidemiol. 2014;179(2):177–185