Geographic variation in one-year recurrent ischemic stroke rates for elderly Medicare beneficiaries in the USA.
BACKGROUND
While geographic disparities in stroke mortality are well documented, there are no data describing geographic variation in recurrent stroke. Accordingly, we evaluated geographic variations in 1-year recurrent ischemic stroke rates in the USA with adjustment for patient characteristics.


METHODS
One-year recurrent stroke rates for ischemic stroke (International Classification of Diseases, 9th Revision codes 433, 434 and 436) following hospital discharge were calculated by county for all fee-for-service Medicare beneficiaries from 2000 to 2002. The rates were standardized and smoothed using a bayesian conditional autoregressive model that was risk-standardized for patients' age, gender, race/ethnicity, prior hospitalizations, Deyo comorbidity score, acute myocardial infarction, congestive heart failure, diabetes, hypertension, dementia, cancer, chronic obstructive pulmonary disease and obesity.


RESULTS
The overall 1-year recurrent stroke rate was 9.4% among 895,916 ischemic stroke patients (mean age: 78 years; 56.6% women; 86.6% White, 9.7% Black and 1.2% Latino/Hispanic). The rates varied by geographic region and were highest in the South and in parts of the West and Midwest. Regional variation was present for all racial/ethnic subgroups and persisted after adjustment for individual patient characteristics.


CONCLUSIONS
Almost 1 in 10 hospitalized ischemic stroke patients was readmitted for an ischemic stroke within 1 year. There was heterogeneity in recurrence patterns by geographic region. Further work is needed to understand the reasons for this regional variability.
Allen
Norrina B
NB
Division of Chronic Disease Epidemiology, Yale University School of Medicine, New Haven,CT 06520-8034, USA.
Holford
Theodore R
TR
Bracken
Michael B
MB
Goldstein
Larry B
LB
Howard
George
G
Wang
Yun
Y
Lichtman
Judith H
JH
D001741:Black or African American; D000367:Age Factors; D000368:Aged; D001499:Bayes Theorem; D002545:Brain Ischemia / Q000453:epidemiology*; D015331:Cohort Studies; D005260:Female; D005843:Geography; D006630:Hispanic or Latino; D006801:Humans; D008297:Male; D006278:Medicare; D044469:Racial Groups; D012008:Recurrence; D012044:Regression Analysis; D012307:Risk Factors; D012737:Sex Factors; D020521:Stroke / Q000453:epidemiology*; D013997:Time Factors; D014481:United States / Q000453:epidemiology; D044465:White People