Ischemic Stroke Following Transient Ischemic Attack: Sociodemographic and Clinical Risk Factors in a National Cohort.
TL;DR
Early ischemic stroke after TIA remained associated with both established vascular risk factors and African American race after adjustment for income, insurance status, and major clinical covariates, suggesting that short term post TIA stroke risk may reflect both clinical risk burden and additional patient level or care process factors not captured by routine socioeconomic measures.
Abstract
INTRODUCTION Transient ischemic attack (TIA) often precedes ischemic stroke, and the risk of recurrence is highest in the first days to weeks after the initial TIA. Although sociodemographic and socioeconomic factors are associated with stroke incidence, care, and long term outcomes, their relationship to very early progression from TIA to ischemic stroke remains less well defined.
Methods
We performed a retrospective cohort study using the National Institutes of Health All of Us Research Program. Adults with TIA were identified using predefined SNOMED, ICD-9-CM, and ICD-10-CM concept codes and were followed for 30 days for subsequent ischemic stroke. Covariates included race, sex at birth, age, income, insurance status, smoking status, hypertension, diabetes mellitus, atrial fibrillation, and carotid stenosis. Multivariable logistic regression was used to evaluate adjusted associations with 30 day ischemic stroke. Model discrimination was assessed using the C-statistic, and calibration was assessed using the Hosmer-Lemeshow goodness of fit test. Interaction terms between race and sex, income, and insurance status were evaluated using likelihood ratio testing.
Results
Among 19,241 participants with TIA, 3,900 (20.3%) experienced ischemic stroke within 30 days. African American race was associated with higher odds of 30 day stroke compared with White race (adjusted odds ratio [aOR] 1.281, 95% confidence interval [CI] 1.157 to 1.419; p < 0.001). Female sex showed a trend toward lower odds that did not reach conventional significance (aOR 0.933, 95% CI 0.863 to 1.010; p = 0.086). Hypertension, diabetes mellitus, atrial fibrillation, and carotid stenosis were independently associated with increased 30 day stroke risk. Income categories showed inconsistent associations without a consistent directional trend, and insurance status was not independently associated with stroke after adjustment. Interaction terms between race and sex, income, and insurance did not significantly improve model fit (likelihood ratio test p = 0.690).
Conclusion
In this national cohort, early ischemic stroke after TIA remained associated with both established vascular risk factors and African American race after adjustment for income, insurance status, and major clinical covariates. These findings suggest that short term post TIA stroke risk may reflect both clinical risk burden and additional patient level or care process factors not captured by routine socioeconomic measures.