Hospital-Level Medicaid Prevalence Is Associated with Increased Length of Stay after Asymptomatic Carotid Endarterectomy and Stenting Despite no Increase in Major Complications

Abstract

Length of stay (LOS) after carotid endarterectomy (CEA) and carotid artery stenting (CAS) for asymptomatic disease is used as a quality measure and affects hospital operating margins. Patient-level Medicaid status has traditionally been associated with longer hospital LOS. Our goal was to assess the association between hospital-level Medicaid prevalence and postoperative LOS after CEA and CAS. The National Inpatient Sample was queried from 2006-2014 for CEA and CAS performed for asymptomatic carotid stenosis. Overall hospital-level Medicaid prevalence was divided into quartiles. The quartiles were further categorized into low Medicaid prevalence (LM) (lowest quartile), medium Medicaid prevalence (MM) (second and third quartiles), and high Medicaid prevalence (HM) (fourth quartile) cohorts. The primary outcome evaluated was postoperative LOS >1day. The secondary outcomes included perioperative/in-hospital complications and mortality. There were 984,283 patients with asymptomatic carotid stenosis who underwent CEA (88%) or CAS (12%). Mean postoperative LOS after CEA at hospitals with LM, MM, and HM prevalence was 1.4±1.5, 2.1±2.5, and 2.2±2.8days (P=0.0001), respectively, and after CAS were 1.7±2.6, 1.8±2.1, and 2±2.6days (P<0.0001), respectively. After CEA, relative to LM prevalence, MM (OR 1.62, 95% CI 1.17-2.24) and HM (OR 1.66, 95% CI 1.2-2.28) prevalence were associated with a higher likelihood of LOS>1day (P=0.009). After CAS, relative to LM prevalence, HM prevalence was associated with a higher likelihood of LOS >1day (OR 1.42, 95% CI 1.06-1.91) (P=0.003). After CEA, neurologic (0.8% vs. 0.9% vs. 0.9%, P=0.83) and cardiac complications (0.9% vs. 1.2% vs. 1.2%, P=0.24) were similar among hospitals with LM, MM, and HM prevalence, respectively. After CAS, the prevalence of neurological (1.1% vs. 1% vs. 1.2%, P=0.42) and cardiac complications (2% vs. 1.3% vs. 1.5%, P=0.46) were also similar. After both CEA and CAS, mortality was similar among Medicaid prevalence cohorts. Higher hospital-level Medicaid prevalence was associated with longer LOS after CEA and CAS for asymptomatic carotid stenosis. Value-based payment models should adjust for hospital-level Medicaid prevalence to appropriately reimburse providers and hospital with higher Medicaid prevalence as well as investigate care pathways and systems improvement to help reduce LOS.