Table 1.

Overview and assessment of prediction models of recurrent acute ischemic stroke in patients with carotid stenosis.

	ECST medical model (6, 22)	SCAIL (23)
Model characteristics	• 11 predictors • Target group: patients with TIA/ischemic stroke and 50–99% stenosis • Prediction horizon: 5 years • Outcome: ipsilateral ischemic stroke • Method: Cox proportional hazards	• 2 predictors (or 9 predictors by correction for clinical parameters) • Target group: patients with TIA/ minor ischemic stroke and 50–99% stenosis • Prediction horizon: 90 days • Outcome: ipsilateral ischemic stroke • Method: Cox proportional hazards
Development	• Derivation population: symptomatic patients (ischemic stroke/TIA) with 50–99% stenosis + EPV ~ 12 - Handling of missing values not reported - Derivation data no longer reflecting ischemic stroke risk with current best medical treatment ± Simplified risk scores	• Derivation population: symptomatic patients (minor ischemic stroke/TIA) with ≥50% stenosis - EPV < 2 (n of candidate predictors unclear) - No censoring of patients with CEA ± Simplified risk scores
Validation	• Validation population: Symptomatic patients (TIA or ischemic stroke) with 50–99% stenosis - No internal validation - Validation by same authors in same paper	• Validation population: Symptomatic patients (minor ischemic stroke/TIA) with ≥50% stenosis - Low number of events - 9-factor model was used - Validation by same authors in same paper
Performance	+ Good calibration - No C-statistic given - No sensitivity or specificity reported	+ High C-statistic - Unclear what the performance of the 2-predictor model is
Feasibility	+ Web-based calculator available - No disclaimer and no access to explanatory texts on website	+ Only 2 predictors (without correction for clinical parameters) - Low face validity - PET/CT is expensive and patients are exposed to ionizing radiation
Overall risk of bias	High risk of bias - Data collection prior to current best medical treatment - No clear performance indicators	High risk of bias - Very low EPV - Validation performed with low number of events - Long-term prognostic power for patients with carotid stenosis not yet clear