Comparison of Hospitalization Costs and
Medicare Payments for Carotid Endarterectomy
and Carotid Stenting in Asymptomatic Patients
BACKGROUND AND PURPOSE: Hospitals struggle to provide care for elderly patients based on Medi-
care payments. Amid concerns of inadequate reimbursement, we sought to evaluate the hospitaliza-
tion costs for recipients of CEA and CAS placement, identify variables associated with increased costs,
and compare these costs with Medicare reimbursements.
MATERIALS AND METHODS: All CEA and CAS procedures were extracted from the 2001–2008 NIS.
Average CMS reimbursement rates for CEA and CAS were obtained from www.CMS.gov. Annual
trends in hospital costs were analyzed by Sen slope analysis. Associations between LOS and hospital
costs with respect to sex, age, discharge status, complication type, and comorbidity were analyzed by
using the Wilcoxon rank sum test. Least-squares regression models were used to predict which
variables had the greatest impact on LOS and hospital costs.
RESULTS: The 2001–2008 NIS contained 181,200 CEA and 12,485 CAS procedures. Age and sex were
not predictive of costs for either procedure. Among favorable outcomes, CAS was associated with
significantly higher costs compared with CEA (P ? .0001). Average Medicare payments were $1,318
less than costs for CEA and $3,241 less than costs for CAS among favorable outcomes. Greater
payment-to-cost disparities were noted for both CEA and CAS in patients who had unfavorable
CONCLUSIONS: The 2008 Medicare hospitalization payments were substantially less than median
hospital costs for both CAS and CEA. Efforts to decrease hospitalization costs and/or increase
payments will be necessary to make these carotid revascularization procedures economically viable for
hospitals in the long term.
ABBREVIATIONS: ARF ? acute renal failure; CAS ? carotid artery stent; CC ? comorbid condition;
CCS ? clinical classification software; CEA ? carotid endarterectomy; CHF ? congestive heart
failure; CMS ? Centers for Medicare & Medicaid Services; COPD ? chronic obstructive pulmonary
disease; CREST ? Carotid Revascularization Endarterectomy versus Stent placement Trial; CRF ?
chronic renal failure; CV, cardiovascular; CVD ? cardiac valve disease; DM ? diabetes mellitus;
DRG ? diagnosis related group; GAPICC ? group average payer inpatient cost-to-charge; HCUP ?
Healthcare Cost and Utilization Project; HHC ? home health care; HLD ? hyperlipidemia; HSD ?
honestly significantly different; HTN ? hypertension; ICD9 ? international classification of dis-
eases, 9th edition; IQR ? interquartile range; LOS ? length of stay; MI ? myocardial infarction;
NIS ? National Inpatient Sample; SNF ? skilled nursing facility; STH ? short-term hospitalization
sclerotic carotid artery stenosis.1Although CEA remains the
ployment has gained support over the past decade. Outcomes
from the recent CREST revealed that patients older than 69
years of age had better outcomes with CEA, while patients
younger than 69 years of age had better outcomes with stent
placement.2Although the results from CREST demonstrate
clinical utility for both therapeutic modalities, particularly
ist to identify potential disparities between costs and reim-
bursements among both favorable and unfavorable postoper-
ative outcomes. As asymptomatic presentations represent
arotid revascularization therapies have been shown to re-
duce the incidence of stroke among patients with athero-
fewer confounding peri-procedural cost variables, we focused
our cost analysis on this subset of individuals. In the current
study, we evaluated the NIS data from 2001 to 2008 to ascer-
tain costs associated with hospitalization for carotid revascu-
larization in asymptomatic patients in order to identify vari-
reimbursements are sufficient to account for these costs.
Materials and Methods
ICD-9 procedure codes were used to independently identify cases of
CEA (38.12, available from 2001–2008) and CAS (00.63, available
from 2004–2008) from the 2001–2008 NIS hospital discharge data
base (Healthcare Cost and Utilization Project of the Agency for
Healthcare Research and Quality, Rockville, Maryland).3Age, sex,
charges, and hospital-specific mean cost-to-charge ratios were ex-
tracted from the NIS dataset for each procedure (CEA, CAS). Dis-
Received April 10, 2011; accepted after revision June 10.
From the Clinician Investigator Training Program (R.J.M.), Department of Radiology (R.J.M.,
D.F.K., H.J.C.), College of Medicine, Mayo Clinic, Rochester, Minnesota.
Please address correspondence to Robert J. McDonald, MD, PhD, Department of Radiology,
Mayo Clinic, 200 1st St SW, Rochester, MN 55905; e-mail: firstname.lastname@example.org
McDonald ? AJNR 33 ? Mar 2012 ? www.ajnr.org
be more reflective of the true costs of hospitalization for each
of the respective procedures. Fourth, although we provide the
hospital charge data in Fig 1, caution is urged in using this
metric, as hospital costs are a more reliable measurement of
the normalized expenditure for each procedure.
Our findings indicate that typical costs for hospitalization for
less of outcome. Efforts to decrease hospitalization costs and/or
increase payments will be necessary to make these carotid revas-
Disclosures: David Kallmes—UNRELATED: Grants/Grants Pending: eV3, Micrus, MicroVen-
tion, NFocus, Sequent, Cook, ArthroCare, Stryker; Royalties: UVA patent foundation,
Comments: Fusion patent; Payment for Development of Educational Presentations: CareFu-
sion, eV3. Harry J. Cloft—UNRELATED: Grants/Grants Pending: Cordis.* (*Money paid to
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AJNR Am J Neuroradiol 33:420–25 ? Mar 2012 ? www.ajnr.org