Leifheit-Limson, Erica C

Background: Over 9 million dual-eligible beneficiaries rely on both Medicare and Medicaid to obtain critical medical services. Medicaid serves as a safety net for low-income Medicare beneficiaries with limited assets; however, it is unknown whether dual-eligible patients have comparable outcomes for procedures to non-dual-eligible Medicare beneficiaries. We compared outcomes by dual-eligible status for patients undergoing carotid endarterectomy (CEA). Methods: We identified Medicare fee-for-service beneficiaries aged ≥65y who underwent CEA (ICD-9 38.12) from 2003-2010. Beneficiaries with ≥1m of Medicaid coverage were considered dual eligible. We fit mixed models with a random intercept for state and adjustment for demographics, comorbidities, and symptomatic status to assess the relationship between dual-eligible status and outcomes. Results: A total of 35,832 dual-eligible and 470,134 non-dual-eligible beneficiaries were hospitalized for CEA during the study period. The percentage of dual-eligible CEA patients decreased from 7.9% in 2003 to 6.7% in 2010. Dual eligibles were more likely to be younger, female, of nonwhite race, and living with comorbid conditions (e.g., heart failure, renal failure, diabetes) and symptomatic carotid disease. Dual eligibles had higher 30d composite outcomes including stroke (Table), but the associations with 1y stroke became nonsignificant from 2003-2010. Dual-eligible status was associated with higher 30d and 1y mortality after CEA throughout the study period. Conclusions: Dual-eligible Medicare-Medicaid beneficiaries had worse short-term stroke and mortality outcomes than other beneficiaries, even after adjustment for comorbidities. Our results indicate a need to understand factors contributing to poorer outcomes. Challenges include the split accountability between the two programs and the diverse sociodemographics, clinical characteristics, and generally poorer health of the patients.

Background: Carotid endarterectomy (CEA) is the leading procedure for carotid stenosis, yet national data on trends in rates and outcomes are limited. We determined CEA rates among Medicare beneficiaries and evaluated mortality and readmission over 8 years. Methods: We used Medicare fee-for-service data to identify beneficiaries aged ≥65y who had their first CEA (ICD-9 38.12) from 2003-2010 and calculated annual rates per 100,000 person-years (PY). We fit mixed models to assess trends in patient-level outcomes, adjusting for demographics, comorbidities, and symptomatic status. We also evaluated hospital-level trends by calculating risk-standardized mortality (RSMR) and readmission (RSRR) rates. A spatial mixed model adjusted for age, sex, and race was fit to calculate county-specific risk-standardized CEA rates in 2003-2004. Results: There were 505,966 unique CEA hospitalizations. The annual number of CEA discharges decreased from 81,604 in 2003 to 47,597 in 2010 (42% decrease), though the patient characteristics remained largely similar. The national CEA rate was 283 per 100,000 PY in 2003, and there was considerable geographic variability (Figure A). This rate decreased each year to a low of 172 per 100,000 PY in 2010. The rate of stroke or death within 30 days decreased from 3.2 to 2.7%, with a significant adjusted annual reduction of 3% (Figure B). Annual reductions in other short- and long-term outcomes were similar, ranging from 2-3%. The median hospital-level 30-day RSMR decreased over time from 0.99 to 0.57%, while the variation between hospitals increased (interquartile range of 0.7-1.67 percentage points). The 30-day RSRR decreased from 11.0 to 10.1%, but there was more homogeneity across hospitals and years. Conclusions: CEA use among Medicare patients decreased dramatically from 2003-2010, while mortality and readmission outcomes improved. The relative importance of biological and sociological mechanisms for these trends merits further study.

Background: CREST, a randomized trial comparing carotid artery stenting (CAS) with endarterectomy (CEA) in symptomatic and asymptomatic patients, reported in 2010 that the two procedures were similar for the composite endpoint of stroke, myocardial infarction, or death. Data on temporal trends in the use of these procedures in the US are limited, particularly by sex, race, and geographic region. We reviewed trends in utilization of CAS and CEA for ischemic stroke patients. Methods: Ischemic stroke hospitalizations (ICD-9 433, 434, 436) were identified for patients aged ≥18 years from the Nationwide Inpatient Sample 2007-2011 (N=480,375). Annual trends of CAS and CEA were estimated using mixed models that adjusted for patient age and comorbidities. Models were stratified by sex, race (white, black, other), and 9 geographic regions. Results: Overall, the proportion of stroke patients who received CAS remained relatively stable over time (2.7% in 2007 to 2.8% in 2011) while the proportion who received CEA decreased (from 21.0% to 16.3%). CAS rates increased in the three Central Regions (East North, East South, and West South) but decreased in New England; CEA declines were similar across regions. In adjusted analyses, CAS rates increased slightly for white men, decreased for men and women of other race, but remained stable for the remaining groups (Figure); CEA rates decreased for all sex-race groups. These patterns by sex and race subgroups were generally consistent across geographic regions. Conclusions: The proportion of hospitalized stroke patients receiving CEA decreased over time while CAS rates remained relatively stable, with slight increases seen in the Central regions of the US. There are sex-race differences in the proportion of patients who receive these procedures, but these patterns are largely similar across regions.