External Validation of the PREMISE Score in the Athens Stroke Registry

A simple score was proposed recently for Predicting Early Mortality from Ischemic Stroke (PREMISE) derived from the Austrian Stroke Unit Registry. This score could be useful in clinical practice and research. However, its generalizability is uncertain, as it was validated internally only.

We aimed to validate the PREMISE score externally.

The analysis was performed in the Athens Stroke Registry. The PREMISE score was calculated as described in the original publication. The outcome was death within 7 days after stroke. Logistic regression analysis was used to estimate the relative death risk in different strata of the PREMISE score using the lowest values of the score (ie, 0-4) as the reference category. We assessed the score's calibration by the Hosmer-Lemeshow goodness-of-fit test and its discriminatory power by calculating the area under the receiver operating characteristics curve (AUC).

In 2608 consecutive patients (median age 71 years, 38.8% women) with acute ischemic stroke treated in the stroke unit, mortality increased with increasing PREMISE score from .1% (95% confidence intervals [95% CI]: 0%-.2%) in patients with a score of 0-4 to 28.2% (95% CI: 14.1%-42.3%) in patients with a score of ≥10. The risk for death was more than 6 times higher in patients with a PREMISE score of ≥10 compared to patients with 0-4 points (odds ratio [OR]:6.21, 95% CI:4.13-8.29). Τhe PREMISE score showed excellent calibration (Hosmer-Lemeshow χ²: .01, P= .99) and good discriminatory power (AUC .873, 95% CI: .844-.901).

The present study confirms the prognostic accuracy of the PREMISE score in an independent cohort of patients with acute ischemic stroke treated in the stroke unit.