Does race predict stroke readmission? An analysis using the truncated negative binomial model.
BACKGROUND
Although it is known that the risk of first-ever stroke is higher for blacks than for whites, it is unclear what their relative risk is for stroke recurrence.


METHODS
Using statewide inpatient data from California, 4,784 blacks and 33,684 whites having one or more stroke admissions during the year 2000 were identified. For blacks and whites, age- and sex-adjusted incidence rates were calculated for the index stroke admission using direct standardization (to the U.S. resident population for the year 2000). Various statistical models for count data were applied, with the best one being used in subsequent age-specific multivariate analyses for the number of stroke admissions.


RESULTS
For the index stroke admission, the age- and sex-adjusted incidence rate per 100,000 was 366 (95% CI 355-377) for blacks and 204 (95% CI 202-207) for whites. Those having two or more stroke admissions accounted for less than 20% of the total number of patients. The truncated negative binomial (TNB) model gave the best fit not only to the California data but also to the data reanalyzed from several prior studies done in various countries [i.e., the United Kingdom (Oxfordshire and South London), Switzerland (Lausanne). Australia (Western Australia) and the United States (Nueces County, TX)]. In this study, predictors of stroke readmission changed according to age. For those aged 65-74 years old, blacks showed a higher risk of readmission than whites by 40% after adjustment for patient and hospital factors (RR 1.40, 95% CI 1.19-1.64). This excess risk was lower in other age groups.


CONCLUSIONS
These findings suggest that blacks remain a high-risk group after an initial stroke and warrant appropriate intervention. Future studies on recurrent stroke should consider age-specific TNB models.
Kennedy
Byron S
BS
Department of Epidemiology and Public Health, Yale University School of Medicine, New Haven, CT 06511, USA. byron.kennedy@yale.edu
D000293:Adolescent; D000328:Adult; D001741:Black or African American / Q000706:statistics & numerical data*; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D015331:Cohort Studies; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D015999:Multivariate Analysis; D010359:Patient Readmission / Q000706:statistics & numerical data*; D016012:Poisson Distribution; D011237:Predictive Value of Tests; D011379:Prognosis; D012008:Recurrence; D012042:Registries; D018570:Risk Assessment; D012720:Severity of Illness Index; D017678:Sex Distribution; D020521:Stroke / Q000175:diagnosis / Q000208:ethnology* / Q000628:therapy*; D016019:Survival Analysis; D044465:White People / Q000706:statistics & numerical data*