Guy's Score for Stroke Survival
You are asking about the wrong scoring system—there is no "Guy's score for stroke survival." Guy's prognostic score (also called Guy's Hospital Score) is a stroke risk prediction tool for estimating the probability of having a first stroke, not for predicting survival after stroke has already occurred 1.
What Guy's Score Actually Measures
Guy's prognostic score predicts the risk of experiencing an initial stroke in stroke-free individuals, not survival after stroke 1. This is a primary prevention tool, not a post-stroke outcome predictor.
Correct Tools for Predicting Stroke Survival
If you need to predict survival or functional outcomes after an ischemic stroke has occurred, you should use:
For Immediate Prognostication (Acute Phase)
- The NIH Stroke Scale (NIHSS) is the single most important predictor of stroke outcomes, with scores >16 forecasting high probability of death or severe disability, whereas scores <6 forecast good recovery 2, 3, 4.
- The NIHSS should be performed at presentation, within 24 hours of admission, and at discharge to guide treatment decisions and predict outcomes 3.
- The NIHSS has the highest predictive accuracy (area under curve 0.83) compared to other acute stroke scales, and adds significantly more prognostic information than any other scoring system 1.
- A baseline NIHSS score is essential for prediction of acute ischemic stroke outcomes, contributing 11.3% to 25.0% of explained variation in outcomes, far exceeding the contribution of comorbidity indices (0.7-4.0%) 4.
For Comprehensive Survival Prediction
- The Ischemic Stroke Survival Score combines multiple domains including the Scandinavian Stroke Scale, Rapid Disability Rating Scale, age, and prior stroke history, achieving substantially greater predictive power (R²=0.30, c statistic=0.86) than single-domain measures 5.
- This multi-domain approach assessed at day 7 post-stroke provides superior 12-month survival prediction compared to neurological scales alone 5.
Alternative Validated Prognostic Scores
- The PLAN score (preadmission comorbidities, level of consciousness, age, and neurological deficit) demonstrates excellent performance with area under curve of 0.92 for poor functional outcomes and 0.87 for in-hospital mortality 6.
- The IScore and ASTRAL score also perform well, with area under curves of 0.86-0.88 for mortality prediction 6.
Common Pitfall
Do not confuse Guy's prognostic score (primary stroke prevention) with post-stroke survival prediction tools. Guy's score was developed to identify stroke-free individuals at risk of having their first stroke, not to predict outcomes in patients who have already suffered a stroke 1.