(IP199) Creating a Cost Model for Carotid Endarterectomy Based on Vascular Quality Initiative and Medicare Claims Data

Objectives: Medicare payments now comprise 14% of the US budget, and care associated with surgery now comprises a majority of claims. Carotid care alone is valued at nearly $1 billion dollars, and it is imperative to better understand the drivers of these costs in contemporary practice. We aim to create a model that predicts the reimbursed cost of inpatient stays for patients with carotid artery stenosis who undergo a carotid endarterectomy (CEA) or carotid stenting (CAS), and qualitatively evaluate the utility of a cost-calculator tool powered by this model for use by surgeons.

Methods: The Medicare-linked Vascular Quality Initiative registry was queried to identify patients who underwent CAS or CEA between 2010-19. Each procedure-group was each divided into three groups - ““with complication/comorbidity(CC),” “with major complication/comorbidity(MCC),” and without CC/MCC.” We modelled the individual effect of preoperative and postoperative variables on cost using a bootstrap method with 100 samples.

Results:

Results: Included were 85,970 CEA patients; 54,470 patients were without CC/MCC, 24,966 were with CC, and 6,534 were with MCC. Also included were 23,705 CAS patients, 13,021 without CC/MCC, 7,923 with CC, and 2,761 with MCC. The mean cost of CEA in the group was $6,562 and the mean cost of CAS was $9,665. Complications increased the cost of both CEA and CAS – patients with CC had a $2648 increase in CEA cost and $2556 increase in CAS cost, while patients with MCC had a $11,236 increase in CEA cost and a $9473 increase in CAS cost [Figure 1,2]. Chronic obstructive pulmonary disease was associated with decreased costs in CEA (-$225) and CAS (-$207). Prior major limb amputation was associated with increased costs in CEA (+$601) and CAS (+$779). Postoperative complications also drove cost increases – in CEA, postoperative stroke caused an increased cost of $107, although in CAS, stroke did not contribute significantly to cost. New postoperative congestive heart failure (CHF) was the largest driver of increased cost in CEA (+$1462) and CAS (+$3264). Correlation coefficients for the CEA and CAS models were r=0.507 and r=0.417, both strong associations with p< 0.001.

Conclusions: Medicare costs for carotid endarterectomy versus stenting vary widely, with MCC, dialysis, and postoperative CHF being major drivers of increased cost. Surprisingly, a number of cardiopulmonary comorbidities are associated with decreased cost, perhaps due to vigilant perioperative specialist management. Current understanding of cost by providers is limited, and would benefit from interactive tools to model patient-level costs in real time.