A new clinical score to predict the possibility of stroke patients receiving intravenous thrombolysis.

Background: We aimed to develop and validate a clinical score to identify the factors which contribute to variation in, and influence clinician's decision-making about treating acute ischemic stroke (AIS) patients with Intravenous thrombolysis (IVT).

Methods: We retrospectively included consecutive AIS patients within 4.5 hours after onset in the emergency department (ED), who were admitted to a comprehensive stroke center in Jiangsu province, China. The patients were randomly divided into derivation (60%) and validation data sets (40%) to develop and validate the clinical score. Multivariable stepwise forward logistic regression was performed to identify the independent predictors of IVT offering in the derivation data.

Results: Out of 526 included patients, 418 patients received thrombolytic therapy. Nine patient factors were associated with the likelihood of thrombolysis (age, time to hospital, National Institute of Health stroke scale (NIHSS) score, great vessel, facial paralysis, dizziness, headache, history of stroke, and neutrophil ratio). The c-statistics of the Intravenous Thrombolysis Score in the derivation cohort (n= 316) and validation cohort(n = 210) were 0.795 and 0.751, respectively. The performance of the scoring model was validated with a calibration plot showing good predictive accuracy for the scores in the derivation data (calibrated P = 0.861) and validation data (calibrated P = 0.876).

Conclusions: The Intravenous Thrombolysis Score for predicting the possibility of offering IVT to AIS patients indicates that clinicians differ in their thresholds for the treatment across a number of patient-related factors, which will be linked to training professional development programmes and address the impact of non-medical influences on decision-making using evidence-based strategies.