Comparison of hospitalization costs and Medicare payments for carotid endarterectomy and carotid stenting in asymptomatic patients

Abstract

Background and purpose: Hospitals struggle to provide care for elderly patients based on Medicare payments. Amid concerns of inadequate reimbursement, we sought to evaluate the hospitalization 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 outcomes.

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.

Fig 1.

Annual hospital charges and costs for CEA and CAS. Annual (mean ± SD) unadjusted hospital charges (red circles) and costs (blue circles) are shown for CEA (left) and CAS (right). Sen slope trend-lines are shown for each annual data series (colored lines). 2008 stratified CMS average payments, based upon DRG codes for CEA and CAS, are overlaid in A and B, respectively (Table 2, solid line: no complication or comorbidity; dashed line: minor complication or comorbidity; dotted line: major complication or comorbidity).

Fig 2.

Demographic and outcome variables affecting length of stay and hospital costs for CEA and CAS. Median ± IQR data are shown for LOS (A) and 2008-adjusted hospital costs (B) among preselected demographic and treatment variables for CEA (blue) and CAS (red). Circles represent median values and lines represent interquartile ranges. Tests for significance are color coded as follows: intervariable test CEA vs CAS (black); intravariable tests for CEA (blue) and CAS (red).

Fig 3.

Predictors of length of stay and hospital costs for CEA and CAS by using multivariate regression analysis. Regression estimates for demographic and treatment variables for CEA (blue) and CAS (red) are shown for LOS (A) and 2008-adjusted hospital costs (B). The unadjusted response variable for each model, representing the baseline model value, is represented by the vertical colored lines (CEA, blue; CAS, red). Variable adjustments are shown by positive or negative bar-graph deflections from this baseline value. Regression results for each model are shown. Significance for each variable is coded as follows: ****P < .0001; ***P < .001; **P < .01; *P < .05; NS P ≥ .05).