Diagnostic performance of Glial Fibrillary Acidic Protein and Prehospital Stroke Scale for identification of stroke and stroke subtypes in an unselected patient cohort with symptom onset < 4.5 h

Table 3 Performance of GFAP and PreSS for identification of stroke, ICrH, and LVO

Stroke subtype	Sensitivity% (95% CI)	Specificity% (95% CI)	PPV% (95% CI)	NPV% (95% CI)	LR+ (95% CI)	LR− (95% CI)
GFAP (n = 299)
ICrH	25.0 (11.5–43.4)^a	100.0 (98.6–100.0)^a	100.0 (63.1–100.0)^a	91.8 (88.0–94.6)^a	–	0.75 (0.61–0.92)^a
PreSS part 1 (n = 299) Stroke/TIA suspected if PreSS part 1 ≥ 1
Stroke/TIA	94.4 (89.9–97.3)	17.4 (11.1–25.3)	62.7 (56.6–68.5)	67.7 (48.6–83.3)	1.14 (1.04–1.25)	0.32 (0.16–0.66)
PreSS part 2 (n = 268) LVO suspected if PreSS part 1 ≥ 1 and PreSS part 2 ≥ 2
LVO	55.6 (35.3–74.5)	77.2 (71.4–82.3)	21.4 (12.5–32.9)	93.9 (89.7–96.8)	2.43 (1.62–3.67)	0.58 (0.38–0.88)
PreSS and GFAP combined (as used in the decision tree)
Step 1 Stroke and TIA (Group 4)	94.4 (89.9–97.3)	17.4 (11.1–25.3)	62.7 (56.6–68.5)	67.7 (48.6–83.3)	1.14 (1.04–1.25)	0.32 (0.16–0.66)
Step 2 ICrH (Group 1)	25.0 (11.5–43.4)^a	100.0 (98.6–100.0)^a	100.0 (63.1–100.0)^a	91.8 (88.0–94.6)^a	–	0.75 (0.61–0.92)^a
Step 3 LVO (Group 2)	55.6 (35.3–74.5)^a	82.4 (77.3–86.7)^a	23.8 (14.0–36.2)^a	94.9 (91.3–97.3)^a	3.15 (2.06–4.81)^a	0.54 (0.35–0.83)^a

GFAP glial fibrillary acidic protein, ICrH intracranial hemorrhage, LR+ positive likelihood ratio, LR− negative likelihood ratio, LVO large-vessel occlusion, NIHSS National Institutes of Health Stroke Scale, NPV negative predictive value, PPV positive predictive value, PreSS Prehospital Stroke Score, TIA transient ischemic attack
^aGFAP cutoff set at 5369 pg/mL

ISSN: 1757-7241