ORIGINAL ARTICLE
Cost-utility analysis of prehospital spine immobilization
recommendations for penetrating trauma
Arturo Garcia, MD, Terrence H. Liu, MD, MPH, and Gregory P. Victorino, MD, Oakland, California
The American College of Surgeons’ Committee on Trauma’s recent prehospital trauma life support recommendations against
prehospital spine immobilization (PHSI) after penetrating trauma are based on a low incidence of unstable spine injuries after
penetrating injuries. However, given the chronic and costly nature of devastating spine injuries, the cost-utility of PHSI is
unclear. Our hypothesis was that the cost-utility of PHSI in penetrating trauma precludes routine use of this prevention strategy.
METHODS:
A Markov model based cost-utility analysis was performed from a society perspective of a hypothetical cohort of 20-year-old
males presenting with penetrating trauma and transported to a US hospital. The analysis compared PHSI with observation
alone. The probabilities of spine injuries, costs (US 2010 dollars), and utility of the two groups were derived from published
studies and public data. Incremental effectiveness was measured in quality-adjusted life-years. Subset analyses of isolated head
and neck injuries as well as sensitivity analyses were performed to assess the strength of the recommendations.
RESULTS:
Only 0.2% of penetrating trauma produced unstable spine injury, and only 7.4% of the patients with unstable spine injury
who underwent spine stabilization had neurologic improvement. The total lifetime per-patient cost was $930,446 for the
PHSI group versus $929,883 for the nonimmobilization group, with no difference in overall quality-adjusted life-years.
Subset analysis demonstrated that PHSI for patients with isolated head or neck injuries provided equivocal benefit over
nonimmobilization.
CONCLUSION:
PHSI was not cost-effective for patients with torso or extremity penetrating trauma. Despite increased incidence of unstable
spine injures produced by penetrating head or neck injuries, the cost-benefit of PHSI in these patients is equivocal, and further
studies may be needed before omitting PHSI in patients with penetrating head and neck injuries. (J Trauma Acute Care Surg.
2014;76: 534Y541. Copyright * 2014 by Lippincott Williams & Wilkins)
LEVEL OF EVIDENCE: Economic and value-based evaluation, level II.
KEY WORDS:
Prehospital spine immobilization; spinal cord injury; penetrating trauma; unstable spine injury; cost-utility analysis.
BACKGROUND:
S
pine immobilization in patients with an unstable vertebral
injury can prevent subsequent neurologic deterioration
when the spinal cord is undamaged by the initial trauma. In
blunt trauma, the forces of abrupt deceleration can cause a
disruption of the boney and ligamentous structural support,
resulting in an unstable spinal injury, which can lead to spinal
cord injury when left without immobilization.1 The mechanism
of spine injury in penetrating trauma is different from that of
blunt trauma in that the penetrating object itself causes the
damage to the spinal cord.2 Unstable vertebral injuries are less
common with penetrating trauma, and patients who experience
these injuries as the results of penetrating trauma usually have
also sustained permanent irreversible spinal cord injury from
the initial insult.3 Together, these make spine immobilization
a less effective strategy for spinal cord injury prevention in
penetrating trauma.
Submitted: April 17, 2013, Revised: June 18, 2013, Accepted: September 9, 2013.
From the Alameda County Medical Center, University of California, San FranciscoYEast
Bay, Oakland, CA.
This study was presented at the Academic Surgical Congress, February 5Y7, 2013, in
New Orleans LA.
Supplemental digital content is available for this article. Direct URL citations appear
in the printed text, and links to the digital files are provided in the HTML text of
this article on the journal’s Web site (www.jtrauma.com).
Address for reprints: Arturo Garcia, MD, Department of Surgery, Alameda County
Medical Center, 1411 East 31st St, QIC 22134, 3rd Floor Oakland, CA 946021018; email: [email protected].
DOI: 10.1097/TA.0b013e3182aafe50
534
The benefit of field interventions such as spine immobilization for penetrating trauma patients remains controversial.4 There
has been a paradigm shift toward minimizing field interventions
and prehospital care by emergency medical service providers to
expedite transport to a trauma center to receive definitive care.5Y7
Procedure-driven, time-intensive approach to emergency medical
service care with an emphasis on field stabilization needs to be
balanced with abbreviated scene time and rapid transport time, with
the goal of getting the patient to definitive care in a hospital as
quickly as possible. This balance is one of the cornerstones of
prehospital trauma life support (PHTLS).8
In 2011, the PHTLS programVan educational effort for
emergency medical technicians, paramedics, and nurses sponsored by the National Association of Emergency Medical Technicians and the American College of Surgeon’s Committee on
TraumaVrevised its recommendations for prehospital spine immobilization (PHSI) in cases of penetrating trauma. These new
recommendations stated that there are no data to support routine
PHSI in patients with penetrating trauma to the neck, torso, or
cranium; PHSI should never be performed at the expense of
accurate physical examination or identification and correction of
life-threatening conditions; and PHSI may be performed after
penetrating injury when a focal neurologic deficit is noted on
physical examination, although there is few evidence of benefit
even in these cases.
The new recommendations were based on a literature review
by the PHTLS Executive Committee that found that the overall
incidence of unstable spine injury without spinal cord injury in
J Trauma Acute Care Surg
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J Trauma Acute Care Surg
Volume 76, Number 2
penetrating trauma is low and often reported as zero.3 However, the
prolonged hospitalization, extensive posthospitalization rehabilitation, and lifelong disability encountered by spinal cord injury
patients are expensive and can range from $3 million to more than
$5 million during the life-span of the individual.9 Furthermore,
patients with spinal cord injury have a reduced life expectancy
along with varying degrees of disability, leading to personal opportunity loss and higher societal costs.10 When these societal costs
are taken into consideration, the relative cost-effectiveness (CE)
of PHSI versus nonimmobilization is uncertain.
In light of the chronicity and costs of these devastating
spinal injuries, the objective of this investigation was to compare
the CE of PHSI with no spinal immobilization in patients with
penetrating trauma. Our hypothesis was that the CE of PHSI for
isolated penetrating trauma precludes the routine use of this
prevention method.
PATIENTS AND METHODS
Study Design
Garcia et al.
of penetrating trauma management.33 Spine immobilization
and imaging costs were based on the reimbursement structure
for Medicare as a representative of US payors using actual 2010
Medicare reimbursements.34 Total first-year costs and yearly
health care and living costs for spinal injury patients were
obtained from the National Spinal Cord Injury Statistical
Center, which captures approximately 13% of all national
spinal cord injuries and publishes annual statistical reports
based on their data collection and follow-up surveys of patients
sustaining traumatic spinal cord injuries9 (Table 2). Income
loss caused by paraplegia and tetraplegia was calculated based
on life expectancies of paraplegia and tetraplegia as well as
rates of employment of persons with spinal injury obtained
from the National Spinal Cord Injury Statistical Center combined with earnings data from the Bureau of Labor Statistics
Occupational Employment Statistics.37 Opportunity loss and
cost of living was calculated from published US expectancy
data for the dollar value of the day10 and the Bureau of Labor
Statistics.35 All costs were presented in US 2010 dollars and
were discounted at a rate of 3% per year.
This analysis was performed using a state-transition (Markov)
decision model(Supplemental Figure 1,http://links.lww.com/TA/A351)
from the society prospective. Penetrating injury is more common
in the male population and most commonly occurs in the second
and third decade of life;11 therefore, our study population was
a hypothetical cohort of 20-year-old males sustaining penetrating trauma and transported to a US hospital emergency center
by ambulance. Decision software (TreeAge Pro Healthcare
Module 2011, TreeAge Software, Inc., Williamstown, MA) was
used in the construction and analysis of our decision model. The
cycle time frame for the analysis was 1 year with an analytic horizon that included the life-span of noninjured individuals, based on a life expectancy of 77 years for 20-year-old
males.12 This translates to 57 cycles of the Markov model after
which all states reached death. Patients reaching the death state
before the 57th cycle were kept in the model to calculate
opportunity loss.
Utility Determination
Probabilities of Clinical Events
Subgroup analyses were performed on base-case populations with different rates of spinal cord injury as a function
of the location of penetrating trauma categorized as (1) penetrating injury to the head and face or (2) penetrating injury to
the neck. Probabilistic sensitivity analyses were performed
using Monte Carlo simulation consisting of 100,000 first-order
trials to reflect the sampling uncertainty in the model inputs.
One-way sensitivity analyses were also performed on all cost,
incidence, and utility variables as well as age and discount rate
in the main base-case population as well as the two subgroup
analyses of populations mentioned earlier.
The probabilities of events (Table 1) were derived from a
literature review by the PHTLS Executive Committee, which
identified the incidence and natural history of spine injury
caused by penetrating trauma from a literature search.3
To summarize their methods, the search retrieved Englishlanguage articles from 1989 through 2011 relevant to the identification of prehospital management of spine injuries as a result
of penetrating trauma. MeSH search terms included pre-hospital,
cervical spine, spine injury, and penetrating trauma. Letters
to the editor were excluded. The Cochrane Library online database was also queried for systematic reviews of PHSI and
emergency intubations. Bibliographies of all reviewed articles
were cross-referenced to locate any relevant articles not located
in the MeSH search. Unstable spine injuries were defined as
those identified as unstable or those in which surgical or nonsurgical stabilization was instituted.
Cost Determination
Hospital costs of acute management of trauma were
derived from previously published studies examining the costs
Utilities for individuals with paraplegia and tetraplegia
were obtained from the study of Lin et al.,4 which provides
standard gamble utilities for individuals with traumatic spinal
cord injury. Patients who recovered completely following penetrating trauma were considered to have a health utility state
of 0.75 for 6 months, thereafter returned to a health utility state
of 1 (Table 2). Patients who sustained spinal cord injury resulting in paraplegia were considered to have a permanent health
utility state of 0.75. Patients who sustained spinal cord injury
resulting in tetraplegia were considered to have a permanent
health utility state of 0.39. Patients who died were assigned a
health state of 0. As per the Markov model, health states were
summed over all 57 cycles to obtain quality-adjusted life-years
(QALYs). Utilities were discounted at a rate of 3% per year.
Sensitivity Analysis
Assumptions
Several assumptions were made during the construction
of the analysis. (1) The amount of time it took to place a patient
in the field in spine immobilization was considered to be negligible, and the time to intubation as well as the intubation
complication rate in the PHSI group and the non immobilization
group were assumed to be identical. (2) The risk of computed
tomography radiation-induced malignancies was not considered
during this analysis. (3) Patients with spinal cord injury from
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535
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Garcia et al.
TABLE 1. Review of Evidence
References
Aryan et al.13
Barkana et al.14
Brown et al.15
Chong et al.16
Connell et al.17
Cornwell et al.18
Dubose et al.19
Harrop et al.20
Haut et al.21
Kaups
and Davis22
Kennedyet al.23
Klein et al.24
Kupcha et al.25
Lanoix et al.26
Lustenberger
et al.27
Medzon et al.28
Ramasamy
et al.29
Rhee et al.30
Vadnerlan
et al.31
Vanderlan
et al.32
Total
Study Population
Total
Patients
Penetrating bony
spine injury*
Penetrating
neck injury
GSW to the torso
Any GSW
GSW to the head
GSW to the torso
GSW to the torso
Nonextremity GSW
Complete spinal
cord injury*
Any penetrating
trauma**
GSW to the head
GSW to the head
GSW to the head
GSW to the neck
GSW to the torso
Penetrating cervical
spinal cord injury*
GSW to the head
Penetrating
neck injury
GSW to the
head or neck
Penetrating
neck injury
Any penetrating
trauma†
Penetrating
neck injury†
Penetrating
neck injury
Spinal Cord
Injury, n (%)
Stable Spinal Column
Fracture Without
Cord Injury, n (%)
Unstable Spinal Column
Fracture, n (%)
No Spinal
Injury, n (%)
60
41 (68.3)
19 (31.7)
0 (0.0)
0 (0.0)
44
10 (22.7)
1 (2.3)
3 (6.8)
32 (72.7)
357
75,210
53
1,929
1,000
4,204
182
17 (4.8)
1,040 (1.4)
0 (0.0)
12 (0.6)
73 (7.3)
150 (3.6)
182 (100)
13 (3.6)
2,176 (2.9)
0 (0.0)
0 (0.0)
56 (5.6)
177 (4.2)
V
1 (0.3)
26 (0.0)
0 (0.0)
0 (0.0)
2 (0.2)
0 (0.0)
V
324 (90.8)
71,994 (95.7)
53 (100)
1,902 (98.6)
856 (85.6)
3,865 (91.9)
V
30,956
86 (0.3)
327 (1.1)
116 (0.4)
30,513 (98.6)
215
1 (0.5)
2 (0.9)
0 (0.0)
199 (92.6)
266
363
183
2,136
28
4 (1.5)
7 (1.9)
18 (9.8)
126 (5.9)
28 (100)
1 (0.4)
5 (1.4)
16 (8.7)
60 (2.8)
0 (0.0)
0 (0.0)
7 (1.9)
18 (9.8)
126 (5.9)
0 (0.0)
261 (98.1)
122 (33.6)
150 (82.0)
2,080 (97.4)
0 (0.0)
151
1,069
0 (0.0)
34 (3.2)
0 (0.0)
61 (5.7)
0 (0.0)
4 (0.4)
151 (100)
1,004 (93.9)
81
15 (18.5)
4 (4.9)
3 (3.7)
62 (76.5)
90
16 (17.8)
3 (3.3)
3 (3.3)
70 (77.8)
20,056
125 (0.6)
54 (0.3)
29 (0.1)
V
188
V
V
V
V
196
107,603
7 (3.6)
13 (6.6)
2 (1.0)
181 (92.3)
1,647 (1.5)
2,642 (2.5)
192 (0.2)
83,306 (77.4)
*Only identifies patients with spine injury, not used in analysis.
**Patient population overlaps other study population in data set, not used in analysis.
†Does not identify all spine injuries, not used in analysis.
penetrating neck or head injury were assumed to have tetraplegia
and those with penetrating torso injury were assumed to have
paraplegia. (4) Neurosurgical stabilization procedures and prolonged spine immobilization with rigid cervical spine collar or
spine brace were considered interventions for unstable spine
injury. (5) No penetrating injury recidivism was taken into account in our model.
RESULTS
Base-case analyses of 20-year-old males sustaining penetrating trauma demonstrated that only 0.18% of the penetrating trauma patients had unstable spine injuries that may have
benefited from initial spine immobilization (Table 1). In addition, only 7.44% of the patients with unstable spine injury
536
and who underwent surgical or prolonged nonoperative stabilization had neurologic improvement. PHSI had similar overall
paraplegia and tetraplegia rates compared with nonimmobilization (paraplegia: PHSI, 0.90% vs. no PHSI, 0.91%; relative risk
[RR], 0.98; confidence interval [CI], 0.85Y0.99) (tetraplegia:
PHSI, 0.38% vs. no PHSI, 0.39%; RR, 0.97; CI, 0.89Y0.99) at
1 year. There was no difference in mortality at 1 year between the
two groups (PHSI, 7.99% vs. no PHSI, 7.99%; RR, 1; CI 0.99Y1.0;
Table 2). The total mean lifetime per-patient cost was $930,446 T
$1,253 in the PHSI group versus $929,883 T $1,255 in the
nonimmobilization group (Table 3). The mean QALYs gained
per patient by successful surgical stabilization was 12.87, with
an average cost-savings of $2,451,379 per patient; however,
the mean total health care costs, living costs, and opportunity
loss for a patient with spinal injury and neurologic deficits are
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J Trauma Acute Care Surg
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Garcia et al.
TABLE 2. Incidences, Costs, and Utilities (Includes Living Costs) in US 2010 Dollars
Incidence in No PHSI, % Incidence in PHSI, % First-Year Costs Yearly Costs Opportunity Loss Total Costs
Parameters
Survive initial trauma35
Spinal cord injury*
Unstable spinal injury*
PHSI (direct costs)**
Health states
Full recovery10,32
Paraplegia9*
Tetraplegia9*
Death9,10,24,32,36
92.1
1.5
0.2
0
92.1
1.5
0.2
100
N/A
N/A
$876
90.7
0.91
0.39
7.99
90.7
0.90
0.38
7.99
$66,316
$480,431
$849,041
$96,060
N/A
N/A
N/A
N/A
N/A
N/A
$29,149
$63,643
$138,098
$0
$18,383
$1,010,290
$1,111,356
$1,298,630
N/A
N/A
$876
Utility4
N/A
N/A
N/A
$853,208
0.75 (6 mo)
$3,056,842 0.75
$5,056,842 0.39
$1,346,563
0
*Incidence calculated from data in Table 1.
**Cost of PHSI includes cost of spine imaging33 and cost of cervical collar (estimated from several wholesale options of disposable, adjustable cervical collars).NA, not applicable.
$3,304,587 versus $852,332 for a fully recovered trauma patient without neurologic deficits. Lifetime costs per QALY for
the PHSI group are $36,574 T $64 versus $36,552 T $64 in
the nonimmobilization group.
Sensitivity Analysis
Subset analysis of isolated head and isolated neck injuries
demonstrated that 0.7% of isolated head injury and 1.9% of
isolated neck injury patients had unstable spine injury that could
benefit from initial spine immobilization. The total mean lifetime
per patient cost in isolated head and neck injuries in the PHSI
group were $953,812 T $1,792 and $1,140,630 T $3,515, respectively, versus $954,682 T $1,818 and $1,144,739 T $3,558,
respectively, in the nonimmobilization group. For patients with
isolated penetrating head or neck injuries, routine PHSI was the
dominant strategy over nonimmobilization, but the CIs for the
incremental net benefit (INB) indicate equivocal benefit of PHSI
even in these cases (INB head injury: $1,371; CI, j$5,034 to
$7,776; INB neck injury: $5,106; CI, j$6,107 to $16,315).
Sensitivity and threshold analyses were then performed
on all variables in all three decision trees (all penetrating
trauma, penetrating head trauma, penetrating neck trauma), and
only four variables were found to be sensitive (Figs. 1Y3). Our
finding that PHSI in penetrating trauma is not advantageous is
predominantly dependent on the incidence of unstable spinal
column injury, rate of neurologic recovery after stabilization in
penetrating spine injury, and the cost of routine PHSI (Fig. 1).
In patients with penetrating head or neck injury, there are increased probabilities of unstable spine injuries; therefore, spine
stabilization in these patients may have favorable effects on
patient quality of life and societal burden. Sensitivity analysis
in penetrating head and neck injuries found that varying the
incidence of unstable spinal column injury and the rate of
neurologic recovery after stabilization in penetrating spine
injury may affect the recommendation regarding omitting
PHSI (Figs. 2 and 3). In addition, in penetrating head injury,
varying the cost of spine immobilization and the yearly costs
of tetraplegia may also affect the recommendation regarding
omitting PHSI (Fig. 2).
DISCUSSION
In the current value-based milieu in which medicine is
practiced, CE analyses are becoming increasingly important in
TABLE 3. Expected Costs, Effectiveness, Cost-Utility, and INB
Intervention
Expected
Cost (SE), Dollars
All penetrating trauma
No PHSI**
929,883 (1,255)
Routine PHSI
930,446 (1,253)
Penetrating
head trauma†
No PHSI
954,683 (1,818)
Routine PHSI**
953,812 (1,792)
Penetrating
neck trauma†
No PHSI
1,144,739 (3,558)
Routine PHSI** 1,140,630 (3,515)
Incremental Cost
(95% CI), Dollars
Expected
Utility (SE), QALY
Incremental Utility
(95% CI), QALY
Cost/Utility
(SE), Dollars
INB (95% CI),
Dollars*
V
563 (j2,920 to 4,047)
25.44 (0.01)
25.44 (0.01)
0.00 (NA)
V
36,552 (64)
36,574 (64)
563.44 (j4,311 to 5,437)
V
871 (j4,144 to 5,886)
V
25.32 (0.01)
25.33 (0.01)
V
0.01 (j0.04 to 0.02)
37,708 (73)
37,660 (73)
V
1,371 (j5,034 to 7,776)
4,109 (j5,717 to 13,935)
V
24.35 (0.01)
24.37 (0.01)
V
0.02 (j0.01 to 0.05)
47,014 (165)
46,797 (163)
V
5,109 (j6,107 to 16,325)
*Willingness to pay set at $50,000 per QALY.
**dominance.
†Sensitivity analysis.
NA, not applicable.
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537
J Trauma Acute Care Surg
Volume 76, Number 2
Garcia et al.
Figure 1. Sensitivity analysis of all penetrating injury. Each line
represents the expected total cost associated with PHSI
(solid line) or no immobilization (dashed line) for the 20-year-old
patients. The dot indicates the base-case value, and the
dotted vertical line indicates the threshold at which the costs of
PHSI and no immobilization are equivalent. In all cases, the
difference in QALYs between PHSI and no immobilization is
negligible, and therefore, for any particular variable, the lower
line represents a lower total cost and therefore the preferred
treatment of choice. A, The base-case value of the probability of
unstable spine injury is 0.2%. Omitting PHSI is preferred for
probabilities below the threshold (0.5%). B, As the probability of
neurologic improvement after stabilization in unstable spine
injury patients increases, the benefit of omitting PHSI after
penetrating injury decreases with a threshold of 15.6%
(base case, 7.4%). C, As the cost of spine immobilization
decreases, the benefit of omitting spine immobilization
decreases with a threshold of $407
(base case, $876).
538
medical decision making. The question of the most appropriate care
in penetrating trauma patients with regard to spinal cord injury is
ideal for this type of analysis given its low incidence and potentially
devastating long-term consequences and costs. Initial comparisons
of all patients experiencing penetrating trauma using this Markov
modeled decision analysis suggests that for a cohort of 20-year-old
males presenting with penetrating injury, routine PHSI is more
costly than no PHSI, without a difference in QALYs; therefore,
PHSI is not cost-effective. This is because unstable spine injuries
amenable to surgical or prolonged nonsurgical stabilization are
such rare occurrences in this patient population3,14Y18,21 that even
the large, long-term costs of resulting paraplegia, tetraplegia, and
premature death do not justify routine PHSI.
However, with regard to penetrating head and, more
importantly, neck injuries, there are greater probabilities of
spine injuries than in torso injuries studies.17,20,22,23,29 The
higher vertebral injury incidence is likely caused by the larger
comparative volume of space of the spine compared with
the surrounding tissue creating a proportionally larger at-risk
cross-sectional area for spine injury in penetrating trauma.
Moreover, cervical spine injuries are more costly than thoracic
or lumber spine injuries owing to higher rates of ventilator
dependence, higher cost of care for tetraplegic patients, increased mortality, and lower rates of subsequent employment and quality of life.4,9 Contrary to our hypothesis, subset
analyses of patients with isolated penetrating head or neck
injuries showed that routine PHSI was dominant in comparison
with no PHSI; however, there was no statistically significant
increase in the incremental benefit of PHSI in these patient
populations.
Upon further analysis, we found that the subset analyses of
isolated head and isolated neck injuries may have been skewed by
the findings of Klein et al.,24 which reviewed 2,450 patients with
head, neck, and torso gunshot wounds (GSWs). This single-center
study reported a higher incidence of spinal cord injuries (n = 244,
10%), and specifically unstable spine injuries (151 patients,
6.2%), than rates reported in other studies.15Y21,23,24,26Y29,32 They
also reported many patients requiring prolonged nonsurgical
stabilization for unclear reasons. Although we included these
data in our analysis in an effort to be unbiased to the available
literature, if the data from Klein et al. are disregarded, routine
PHSI is no longer advantageous in patients with penetrating
head injury; however, it still continues to be the dominant strategy in penetrating neck injury.
There are studies suggesting there is an increased mortality associated with spine immobilization in penetrating neck
injuries.20,30 The increased mortality associated with immobilized
patients in these studies was attributed to prolonged scene times
and the potential to miss signs of immediate life threat. Unfortunately, these immediately life-threatening signs are more common in penetrating neck injuries and include missing expanding
hematomas or bleeding, tracheal deviation, and airway compromise. Rates of missed life-threatening injuries caused by cervical
spine immobilization are difficult to quantify and are not available in the published literature. Currently, the model shows a
trend toward an advantage for PHSI in penetrating neck injury,
but the increased rates of complications and mortality with associated PHSI may influence the model such that PSHI is not
cost-effective in this subset of patients.
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J Trauma Acute Care Surg
Volume 76, Number 2
Garcia et al.
Figure 2. Sensitivity analysis of penetrating head injury. Each line represents the expected total cost associated with PHSI (solid line)
or no immobilization (dashed line) for the 20-year-old patients. The dot indicates the base-case value, and the dotted vertical line
indicates the threshold at which the costs of PHSI and no immobilization are equivalent. In all cases, the difference in QALYs between
PHSI and no immobilization is negligible, and therefore, for any particular variable, the lower line represents a lower total cost
and therefore the preferred treatment of choice. A, The base-case value of the probability of unstable spine injury is 0.67%. PHSI
is preferred for probabilities above the threshold (0.33%). B, As the probability of neurologic improvement after stabilization
decreases, the benefit of PHSI after penetrating injury decreases with a threshold of 3.7% (base case, 7.4%). C, As the cost of
spine immobilization increases, the benefit of routine spine immobilization decreases with a threshold of $407 (base case, $876).
D, Decreasing the yearly cost of tetraplegia (base case, $138,098 per year) decreases the benefit of routine PHSI.
With regard to prolonged scene time from PHSI, incorporating adverse effects from increasing time to definitive
treatment would only strengthen our conclusion that routine
PHSI in all penetrating trauma is not cost-effective and again
would likely not change the outcome of our subset analysis in
penetrating head or penetrating neck injuries. As is the case
with missed injuries, the direct effect and costs of prolonged
scene times are difficult to quantify and are not available in the
published literature.
The average energy involved in stab wounds is 36 J,38
whereas even in a low-velocity (213 m/s), low-caliber (0.22
caliber) GSW, the energy involved exceeds 46 J and exceeds
450 J in a standard 9-mm GSW.39,40 Given the increased energy
of GSWs when compared with stab wounds, it is likely that
GSWs are more likely to cause spinal injury. In fact, in those
studies that included all penetrating injuries (GSW and stab
wounds), the majority indicated that most, if not all, of the
spine injuries occurred in patients sustaining a GSW rather
than stab wounds.14,26,28,31 However, a subset analysis could
not be performed on spinal injury in patients sustaining stab
wounds because this group was not separated in most of the
studies that reported both GSWs and stab wounds. Based on
the studies in our analysis, the incidence of spinal injury in
patients with isolated stab wounds is very low, and it is unlikely
that PHSI in stab wound patients is of any benefit from a
clinical and an economic standpoint.
There are limitations to this study. The usefulness of costeffective analyses are dependent on the available literature regarding incidence of outcomes from treatments and costs of
treatments and outcomes. Our outcome probabilities are estimated from a review of the literature and combined analysis of
the data contained in 20 studies. These studies are heterogeneous
and contribute substantial variability to our data. In addition, as
much as possible, the types of injuries were categorized, but this
was difficult to do given the lack of consistent objective definitions of stable and unstable spine injuries in the individual
studies. Moreover, most penetrating trauma patients live in urban areas and have low socioeconomic status that would contribute to lower opportunity loss and lower life expectancy than
that used in the analysis. As is the case with any CE analysis,
the costs and other variables assumed in our analysis can be
expected to vary among institutions and regions.
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539
J Trauma Acute Care Surg
Volume 76, Number 2
Garcia et al.
AUTHORSHIP
A.G. conducted the literature search for this study, which all authors
participated in designing. A.G. and T.H.L. contributed to the data
analysis. A.G. wrote the manuscript. All authors participated in editing.
DISCLOSURE
The authors declare no conflicts of interest.
REFERENCES
Figure 3. Sensitivity analysis of penetrating neck injury. Each
line represents the expected total cost associated with PHSI
(solid line) or no immobilization (dashed line) for the 20-year-old
patients. The dot indicates the base-case value, and the dotted
vertical line indicates the threshold at which the costs of PHSI
and no immobilization are equivalent. In all cases, the difference
in QALYs between PHSI and no immobilization is negligible, and
therefore, for any particular variable, the lower line represents
a lower total cost and therefore the preferred treatment of
choice. A, The base-case value of the probability of unstable
spine injury is 1.89% with a threshold of 0.32%, below which
omitting spine immobilization is preferred. B, As the probability
of neurologic improvement after stabilization decreases, the
benefit of PHSI after penetrating neck injury decreases with a
threshold of 1.2% (base case, 7.4%).
CE analyses are becoming increasingly beneficial for the
evaluation of treatment strategies given the rising costs of health
care and increased awareness for outcomes-based practice. To
our knowledge, this is the only decision analysis conducted
surrounding the question of PHSI in penetrating trauma patients.
To that end, the present model represents the first attempt to
answer this question from a purely cost-benefit standpoint.
In conclusion, in this CE analysis of PHSI, the recent
PHTLS recommendations are substantiated in patients who
present with penetrating injuries. Despite the increased incidence of unstable spine injures produced by penetrating head
or neck injuries, subset analyses of the CE of PHSI in these
patients is still equivocal, and further studies may be needed
before omitting PHSI in patients with penetrating head and
neck injuries.
540
1. Denis F. The three column spine and its significance in the classification of
acute thoracolumbar spinal injuries. Spine. 1983;8:817Y831.
2. Kihtir T, Ivatury RR, Simon R, Stahl WM. Management of transperitoneal
gunshot wounds of the spine. J Trauma. 1991;31:1579Y1583.
3. Stuke LE, Pons PT, Guy JS, Chapleau WP, Butler FK, McSwain NE.
Prehospital spine immobilization for penetrating traumaVreview and
recommendations from the PreHospital Trauma Life Support executive
committee. J Trauma. 2011;71:763Y770.
4. Lin M, Yu W, Wang S. Examination of assumptions in using time tradeoff
and standard gamble utilities in individuals with spinal cord injury. Arch
Phys Med Rehabil. 2012;93:245Y252.
5. Bickell WH, Wall MJ, Pepe PE, Martin RR, Ginger VF, Allen MK, Mattox
KL. Immediate versus delayed fluid resuscitation for hypotensive patients
with penetrating torso injuries. N Engl J Med. 1994;331d:1105Y1109.
6. Shafi S, Gentilello L. Pre-hospital endotracheal intubation and positive
pressure ventilation is associated with hypotension and decreased survival
in hypovolemic trauma patients: an analysis of the national trauma data
bank. J Trauma. 2005;59:1140Y1147.
7. Stiell IG, Nesbitt LP, Pickett W, Munkely D, Spaite DW, Banek J, Field B,
Luinstra-Toohey L, Maloney J, Dreyer J, et al., the OPALS Study Group.
The OPALS Major Trauma Study: impact of advanced life-support on
survival and morbidity. CMAJ. 2008;178:1141Y1152.
8. National Association of Emergency Medical Technicians. Prehospital
Trauma Life Support (PHTLS). 7th ed. St. Louis, MO: Mosby Jems/
Elsevier; 2011.
9. National Spinal Cord Injury Statistical Center, University of Alabama at
Birmingham. 2010 NSCISC Annual Statistical Report. Birmingham 2011.
Available at: https://www.nscisc.uab.edu. Accessed March 23, 2012.
10. Expectancy Data. The Dollar Value of a Day, 2010 Edition. Shawnee
Mission, KS: Expectancy Data; 2010.
11. American College of Surgeons Committee on Trauma. National Trauma
Data Bank Annual Report 2010. Available at: http://www.facs.org/trauma/
ntdb/pdf/ntdbannualreport2010.pdf. Accessed July 20, 2012.
12. Centers for Disease Control and Prevention, National Center for Health
Statistics, Life Expectancy. Available at: http://www.cdc.gov/nchs/faststats/
lifexpec.htm. Accessed July 20, 2012.
13. Aryan HE, Amar AP, Ozgur BM, Levy ML. Gunshot wounds to the spine
in adolescents. Neurosurgery. 2005;57:748Y752.
14. Barkana Y, Stein M, Scope A, Maor R, Abramovich Y, Friedman Z,
Knoller N. Prehospital stabilization of the cervical spine for penetrating
injuries of the neckVis it necessary? Injury. 2000;31:305Y309.
15. Brown JB, Bankey PE, Sangosanya AT, Cheng JD, Stassen NA, Gestring
ML. Prehospital spine immobilization does not appear to be beneficial and
may complicate care following gunshot injury to the torso. J Trauma.
2009;67:774Y778.
16. Chong CL, Ware DN, Harris JH. Is cervical spine imaging indicated in
gunshot wounds to the cranium. J Trauma. 1998;44:501Y502.
17. Connell RA, Graham CA, Munro PT. Is spinal immobilisation necessary for
all patients sustaining isolated penetratin trauma? Injury. 2003;34:912Y914.
18. Cornwell EE, Chang DC, Bonar JP, Campbell KA, Phillips J, Lipsett P,
Scalea T, Bass R. Thoracolumbar immobilization for trauma patients with
torso gunshot wounds: is it necessary? Arch Surg. 2001;136:324Y327.
19. Dubose J, Teixeira PGR, Hadjizacharia P, Hannon M, Inaba K, Green DG,
et al. The role of routine spinal imaging and immobilisation in asymptomatic patients after gunshot wounds. Injury. 2009;40:860Y863.
20. Harrop JS, Sharan AD, Vaccaro AR, Prybylski GJ. The cause of neurologic
deterioration after acute cervical spinal cord injury. Spine. 2001;26:340Y346.
* 2014 Lippincott Williams & Wilkins
Copyright © 2014 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
J Trauma Acute Care Surg
Volume 76, Number 2
21. Haut ER, Kalish BT, Efron DT, Haiser AH, Stevens KA, Kieninger AN,
Cornwell EE 3rd, Chang DC. Spine immobilization in penetrating trauma:
more harm than good? J Trauma. 2010;68:115Y121.
22. Kaups KL, Davis JW. Patients with gunshot wounds to the head do not require
cervical spine immobilization and evaluation. J Trauma. 1998;44:865Y877.
23. Kennedy FR, Gonzalez P, Beitler A, Sterling-Scott R, Fleming AW. Incidence of cervical spine injury in patients with gunshot wounds to the
head. South Med J. 1994;87:621Y623.
24. Klein Y, Cohn SM, Soffer D, Lynn M, Shaw CM, Hasharoni A. Spine
injuries are common among asymptomatic patients after gunshot wounds.
J Trauma. 2005;58:833Y836.
25. Kupcha PC, An HS, Cotler JM. Gunshot wounds to the cervical spine.
Spine. 1990;15:1058Y1063.
26. Lanoix R, Gupta R, Leak L, Pierre J. C-spine injury associated with
gunshot wounds to the head: retrospective study and literature review.
J Trauma. 2000;49:860Y863.
27. Lustenberger T, Talving P, Lam L, Kobayashi L, Inaba K, Plurad D, Branco BC,
Demetriades D. Unstable cervical spine fracture after penetrating neck injury:
a rare entity in an analysis of 1,069 patients. J Trauma. 2011;70:870Y872.
28. Medzon R, Rothenhaus T, Bono CM, Grindlinger G, Rathlev NK. Stability
of cervical spine fractures after gunshot wounds to the head and neck.
Spine. 2005;30:2274Y2279.
29. Ramasamy A, Midwinter M, Mahoney P, Clasper J. Learning the lessons
from conflict: pre-hospital cervical spine stabilization following ballistic
neck trauma. Injury. 2009;40:1342Y1345.
30. Rhee P, Kuncir EJ, Johnson L, Brown C, Velmahos G, Martin M, Wang D,
Salim A, Doucet J, Kennedy S, Demetriades D. Cervical spine injury is
highly dependent on the mechanism of injury following blunt and penetrating assault. J Trauma. 2006;61:1166Y1170.
Garcia et al.
31. Vanderlan WB, Tew BE, McSwain NE. Increased risk of death with cervical
spine immobilisation in penetrating cervical trauma. Injury. 2009;40:880Y883.
32. Vanderlan WB, Tew BE, Seguin CY, Mata MM, Yang JJ, Horst HM, Obeid
FN, McSwain NE. Neurologic sequelae of penetrating cervical trauma.
Spine. 2009;34:2646Y2653.
33. MacKenzie EJ, Weir S, Rivara FP, Jurkovich GJ, Nathens AB, Wang W,
Scharfstein DO, Salkever DS. The value of trauma center care. J Trauma.
2010;69:1Y10.
34. American Medical Association. CPT code/relative value search. Available at: https://catalog.ama-assn.org/Catalog/cpt/cpt_search.jsp. Accessed
July 20, 2012.
35. Bureau of Labor Statistics. Consumer Expenditure Survey Tables. Available at: ftp://ftp.bls.gov/pub/special.requests/ce/standard/2010/cusize.txt.
Accessed July 20, 2012.
36. Dutton RP, Stansbury LG, Leone S, Kramer E, Hess JR, Scalea TM. Trauma
mortality in mature trauma systems: are we doing better? An analysis of
trauma mortality patterns, 1997Y2008. J Trauma. 2010;69:620Y626.
37. Bureau of Labor Statisitics. Consumer Expenditure Survey. Available at:
http://www.bls.gov/cex/#tables. Accessed July 20, 2012.
38. Chadwick EKJ, Nicol AC, Lane JV, Gray TGF. Biomechanics of knife stab
attacks. Forensic Sci Int. 1999;105:35Y44.
39. Robets JC, Ward EE, Merkle AC, O’Connor JV. Asessing behind armor
blunt trauma in accordance with the national institute of justice standard for
personal body armor protection using finite element modeling. J Trauma.
2007;62:1127Y1133.
40. Baik S, Uku JM, Sikirica M. A case of external beveling with an entrance gunshot wound to the skull made by a small caliber rifle bullet.
Am J Forensic Med Pathol. 1993;12:334Y346.
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