COST-EFFECTIVENESS OF CERVICAL SPINE CLEARANCE INTERVENTIONS WITH LITIGATION AND
LONG-TERM CARE IMPLICATIONS IN OBTUNDED ADULT PATIENTS FOLLOWING BLUNT INJURY
Audrey E Ertel MD MS1, Mark H Eckman MD MS2, Bryce RH Robinson MD MS FACS FCCM3
1Department of Surgery, University of Cincinnati, 2Department of Internal Medicine, University of
Cincinnati. 3Department of Surgery, Harborview Medical Center, University of Washington
Background: Controversy exists regarding the appropriate methods to manage cervical spine
immobilization in obtunded trauma patients that cannot participate in clinical clearance exams. The
dominant initial modality for cervical imaging is CT with axial thickness less than 3 mm. 1,2 Because
of sensitivity concerns to detect unstable ligamentous injuries with CT, some groups maintain hard
collar immobilization for prolonged periods of time. These collars have been associated with
pressure ulcer development in up to 38% of patients. Depending on depth and size, pressure ulcers
have significant quality of life and cost implications. Though difficult to estimate, charges for
pressure ulcer care can range from $2 to $44,000 depending on the magnitude of tissue affected
and surgical interventions needed.
The concerns for pressure ulcers have lead some to explore adjunct imaging to CT with the
aim to exclude unstable ligamentous injury. MRI has been proposed as a confirmatory test of CT
due to its high sensitivity for such injuries. Concerns regarding cost and risk incurred by
transporting critically injured patients for MRI in the context of having a negative screening cervical
CT are ongoing.3 Recent Eastern Association for the Surgery of Trauma (EAST) guidelines support
this argument due to an estimated negative predictive value of near 100% for unstable injuries
after a negative, high-quality cervical CT scans. 2 As such, EAST “conditionally recommends” for
cervical collar removal in obtunded patients after a negative high-quality cervical CT. As part of the
guideline creation, the author group determined a priori that a 3 in 1000 (0.003) probability for a
missed, unstable cervical injury after a normal CT was the upper limit for acceptability.
Objectives: Recent guidelines conditionally recommend cervical collar removal after a negative
cervical CT in obtunded adult blunt trauma patients. Though the rates of missed injury are
extremely low, the impact of chronic care costs and litigation upon decision-making remains
unclear. We hypothesize that the costeffectiveness of strategies that include
additional imaging may contradict
current guidelines.
Methods: A cost-effectiveness analysis
was performed for a base case model of a
40-year male with a negative high-quality
cervical CT at the time of initial
evaluation. All injured patients are
obtunded following blunt injury with a
GCS ≤ 12 and assumed to have prolonged
traumatic brain injury (TBI) resulting in
the need for rehabilitation services following inpatient admission. Patients wearing a hard cervical
collar had a quality adjusted life year (QALY) of 0.95 throughout the 6-week period of its use. For
patients who develop pressure ulcers from collar use, the duration of wound care was expected to
1 Audrey E. Ertel University of Cincinnati Department of Surgery
231 Albert Sabin Way, ML 0558, Cincinnati, OH 45267-0558
513-558-5862 phone 513-558-3474 fax Ertel.audrey@gmail.com
be 3 months for stage I-II ulcers after a single operative debridement and 6 months for stage III-IV
ulcers with patients undergoing a total of 3 operative debridements. The major probabilities for
the base case analysis are demonstrated in Table 1. Strategies compared included: adjunct imaging
with cervical MRI, collar maintenance for 6 weeks, or removal. The probability for collar pressure
ulcer formation, spine injury, imaging costs, acute and chronic care, and litigation were obtained
from published and Medicare data. Outcomes were expressed as 2014 US dollars and qualityadjusted life-years (QALYs). Finally, we estimated the probability of medical malpractice claims to
be filed in the setting of an iatrogenic permanent spinal cord injury from collar removal at .25 for
each occurrence. Those claims that progress to litigation were assumed to result in complete
payout of the total claim amount.
mCER ($/QALY)
mCER ($/QALY)
Results: The base case analysis evaluated the cost-effectiveness of three separate strategies for
cervical spine management of a 40 year-old, obtunded, trauma patient following emergency
department evaluation with a negative high-quality cervical CT scan. Quality-adjusted life
expectancy (effectiveness) was similar for all three cervical spine strategies with adjunct MRI
imaging having the highest value of 20.003, followed by removal of cervical collar of 19.995, and
lastly, application of hard cervical collar of 19.989 quality-adjusted life years. Additionally, the
difference in cost between adjuvant
Figure 1
MRI imaging ($361,167.98) was
$800,000
$178.44 less than application of
cervical collar ($361,345.42) and was
$700,000
$660.99 less than removal of cervical
$600,000
collar ($361,828.97). Due to the fact
$500,000
that adjunct imaging with MRI had
$400,000
higher efficacy as well as lower cost,
this strategy dominated all other
$300,000
alternative strategies when evaluating
$200,000
the base case scenario. These results
$100,000
suggest that the appropriate
$0
management for an obtunded patient
0
0.0001 0.0002 0.0003 0.0004 0.0005 0.0006 0.0007
following blunt injury with a negative
Probability of Missed Unstable C-spine Injury
high-quality cervical CT would be to
perform adjunct cervical imaging with
MRI.
Figure 2
A main focus of our analysis
was on the influence of the upper
$175,000
acceptable limit for missed unstable
$150,000
cervical spine injuries upon the cost$125,000
effectiveness of MRI. Previous
6
guidelines set this value at 0.003.
$100,000
Sensitivity analyses were performed
$75,000
upon this metric (Fig 1). With a
$50,000
probability of missed cervical injury
under 0.00001 the most effective and
$25,000
least expensive strategy was removal
$0
of the collar. Taking the cost$0
$500
$1,000
$1,500
$2,000
$2,500
effectiveness threshold of < $50,000
Cost of MRI
per QALY, at a probability of missed
injury of 0.0006, a miss probability 6-
mCER ($/QALY)
fold less than what was previously
Figure 3
accepted, adjunct imaging with MRI was
$25,000
found to be below this threshold (0.0005
= $59,213; 0.0006 = $30,215) as
$20,000
compared with removal of the collar.
Cost associated with MRI was also
$15,000
explored as a function of cost$10,000
effectiveness. Adjunctive imaging with
MRI proves to be the most cost-effective
$5,000
strategy until cost of MRI exceeds $450
(Fig 2). The strengths of adjunct MRI
$0
imaging in our model is based largely on
$0
$40,000 $80,000 $120,000 $160,000 $200,000
the relatively low cost of the test, $223.46
Lifetime Cost of Quadraplegic Patient
per CMS reimbursements. Furthermore,
only when the cost of MRI exceeds $1,050,
does the cost per QALY for adjunctive MRI exceed $50K.
The lifetime costs associated with caring for a patient with a TBI were estimated to be
$299,785.50 compared with $936,438 for those patients who suffer a spinal cord injury resulting in
quadriplegia. The lifetime cost of a quadriplegic patient, even when reduced to $0, would not cause
the addition of MRI screening to exceed the cost-effectiveness threshold when compared to
removal of the collar (Fig 3).
Conclusion: The benefits of early cervical collar removal are easy to recognize. However, the
negatives appear under appreciated by current analyses of the literature that fail to investigate its
impact upon quality-adjusted life years and cost-effectiveness. The cost to society of these
potentially preventable injuries needs to be incorporated into care recommendations. Within our
model, quadriplegics have a reduced length (19.4 vs. 31.4 years) and quality of life (0.572 vs. 0.635
quality of life adjustment) though a dramatically higher cost for lifetime care ($940,000 vs.
$300,000) when compared to obtunded patients with TBI. Sadly, the economics of practicing
medicine in a litigious environment are part of daily practice. Health systems as well as
practitioners would assume significant litigation risk by causing what some may argue is a life
changing iatrogenic injury. Our model assumes that 25% of those that incur an injury proceed with
ligation with a claim rate of 100% for $917,400. With both of these real world cost included in the
analyses, the economics favor MRI. In fact, margin of cost-effectiveness ratio (mCER) values of <
$50,000 favor the use of MRI until this test reaches a cost of approximately $1100, 460% greater
than the current CMS reimbursement rate.
Our preliminary work support the use of adjunct cervical MRI after completion of a negative
high-quality screening CT in obtunded patients following blunt injury. Thorough evaluation of risk
and benefit of current cervical care strategies necessitate the inclusion of analyses utilizing quality
adjusted life years and cost-effectiveness. Future work needs to fill literature voids so that more
complex and accurate decision models can be created in the hope to define the ideal cervical
strategy for each patient but also for society as a whole.
REFERENCES
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2. Patel MB, Humble SS, Cullinane DC, et al. Cervical spine collar clearance in the obtunded adult blunt trauma patient: A systematic
review and practice management guideline from the eastern association for the surgery of trauma. J Trauma Acute Care Surg.
2015;78(2):430-441.
3. Davis JW, Phreaner DL, Hoyt DB, Mackersie RC. The etiology of missed cervical spine injuries. J Trauma. 1993;34(3):342-346.