Same Hospital, Different Outcome: In-Hospital Mortality and Divergent Prognostic Associations in Jewish and Arab Patients with Acute Ischemic Stroke in Northern Israel

Background/Objectives: Individualized risk estimation after stroke depends on prognostic models, which may not transfer between populations. Jewish and Arab patients with acute stroke in the Western Galilee share one regional center and its protocols. We examined whether mortality, prognostic associations of admission variables and pooled-model calibration differ between them. Methods: This retrospective single-center cohort study included adults with non-lacunar acute ischemic stroke and moderate or greater vessel occlusion admitted to the Galilee Medical Center, Israel, from March 2023 to February 2025. The outcome was in-hospital death. Mortality was compared before and after adjustment for age, sex and stroke severity, and prognostic heterogeneity was tested with interaction terms in Firth penalized regression. Results: Of 499 patients, 289 were Jewish and 210 Arab; Jewish patients were older (mean 72.1 versus 67.5 years) and less often current smokers, with similar sex distribution and stroke severity. Mortality was 11.1% in Jewish and 4.8% in Arab patients (risk ratio 2.33, 95% confidence interval (CI) 1.17 to 4.62; adjusted odds ratio 2.05, 95% CI 0.97 to 4.34). In a joint test of age, sex and C-reactive protein (CRP), prognostic associations differed between groups (p = 0.012), mainly because CRP was more weakly associated with death in Jewish patients; white blood cell count showed a similar exploratory pattern. A pooled model without a group term tended to underpredict deaths in Jewish and overpredict them in Arab patients. Conclusions: Within one stroke service, mortality and the prognostic weight of admission variables differed between population groups. These exploratory findings require replication and, if confirmed, would support population-aware validation and recalibration of prognostic models. They concern risk estimation, not treatment, which should follow the same criteria in both groups.