The systemic inflammation score is a prognostic factor for patients with ischemic stroke who have not undergone intravenous thrombolysis or endovascular thrombectomy therapy

Background: The systemic inflammation score (SIS) has been utilised as a representative biomarker for evaluating nutritional and inflammation status. However, the predictive value of SIS has not been reported in patients with acute ischemic stroke (AIS). We aimed to evaluate whether SIS is associated with prognosis in stroke. Methods: A total of 4801 patients with AIS were included in the study. The primary outcome was a modified Rankin Scale score>2 at the 3-month follow-up. A total of 4801 patients were randomly allocated into training (n=3361) and validation cohorts (n=1440) at a ratio of 7:3. Model performance was validated using the receiver operating characteristic (ROC) curve and calibration curve. Additionally, a comparison was made between the nomogram and the THRIVE score in regards to their respective predictive capabilities. Results: Overall, 1091(32.5%) patients in the training cohort and 446 (31.0%) patients in the validation cohort experienced an unfavorable outcome. The multivariate logistic regression analysis revealed that a high SIS, age, NIHSS, diabetes and prior stroke were associated with unfavorable outcome. Our nomogram was developed based on the variables mentioned above. The area under the curve (AUC) of the training set and the validation set are 0.702 and 0.708, respectively, indicating that the model has modest agreement and discrimination. The results of AUC, net reclassification improvement (NRI) and integrated discrimination improvement (IDI) showed that nomogram had significantly higher predictive value than THRIVE scores (all P<0.001). However, unlike the THRIVE publication, all patients who had undergone intravenous thrombolysis or endovascular thrombectomy therapy were excluded in our study. In consequence, our derived THRIVE scores cannot be compared to those in the original THRIVE study. Conclusion: The SIS exhibits potential as a simple prognostic biomarker, and the nomogram, which utilizes the SIS, may serve as a valuable tool for clinicians in the early identification of patients at heightened risk for unfavorable outcomes.