Abstract 13: Improved Ischemic Stroke Outcome Prediction Using Model Estimation Of Outcome Probability: The THRIVE-c Calculator

Introduction: The THRIVE score is a validated ischemic stroke outcome prediction tool. While simplified systems like the THRIVE score facilitate ease-of-use, when computers or devices are available at the point of care, a more accurate estimation of outcome probability is possible by computing the logistic equation with patient-specific continuous variables. Methods: We used data from 12,207 subjects from the Virtual International Stroke Trials Archive (VISTA) and the Safe Implementation of Thrombolysis in Stroke - Monitoring Study (SITS-MOST) study to develop and validate the performance of a model-derived estimation of outcome probability, the THRIVE-c calculation. Models were built with logistic regression using the underlying predictors from the THRIVE score: age, NIH Stroke Scale (NIHSS) score, and the Chronic Disease Scale (presence of hypertension, diabetes mellitus, or atrial fibrillation). Receiver-Operator Characteristics (ROC) analysis was used to assess model performance and compare the THRIVE-c model to the traditional THRIVE score. Results: The THRIVE-c model performed similarly in the randomly chosen development cohort (n=6194, AUC = 0.786, 95% CI 0.774-0.798) and validation cohort (n=6013, AUC = 0.784, 95% CI 0.772-0.796) (P=0.79). The THRIVE-c model (AUC = 0.785, 95% CI 0.777-0.793) had superior performance when compared to the traditional THRIVE score (AUC = 0.746, 95% CI 0.737-0.755), (P Conclusion: By computing the logistic equation with patient-specific continuous variables in the THRIVE-c calculation, patient outcomes are more accurately estimated. Given the widespread availability of the computers and devices at the point of care, such calculations can be easily performed with a simple user interface. A web calculator for THRIVE-c is available at www.thrivescore.org.