To the Editor: In their Rational Clinical Examination article, Drs Runchey and McGee1 summarized the diagnostic accuracy of clinical findings and different stroke scores in distinguishing hemorrhagic and ischemic strokes. The pretest probability (prevalence) of hemorrhagic stroke in the selected studies was 24% (1528 of 6438 patients). A Siriraj score lower than −1 (likelihood ratio [LR], 0.29; 95% confidence interval [CI], 0.23-0.37) or clinician overall impression that hemorrhage is unlikely (LR, 0.28; 95% CI, 0.20-0.39) would decrease the probability of hemorrhage from 24% to 8%, reducing the diagnostic uncertainty but not lowering the likelihood of hemorrhage to a point at which further diagnostic evaluation by neuroimaging may be unnecessary.
Kalantri A, Kalantri S. Distinguishing Hemorrhagic Stroke From Ischemic Stroke. JAMA. 2010;304(12):1327-1328. doi:10.1001/jama.2010.1341