Table 2.

Operating characteristics of C-reactive protein for identifying pneumonia according to different serum values.

Serum CRP (mg/L)	Sensitivity, % (95% CI)	Specificity, % (95% CI)	LR+	LR−
≥50	91.3 (88.7–93.4)	43.9 (38.9–49.1)	1.6 (1.4–1.7)	0.2 (0.1–0.2)
≥100	82.4 (79.0–85.3)	72.3 (67.6–76.7)	3 (2.5–3.5)	0.2 (0.2-0.2)
≥150	65.1 (61.1–69.0)	87.16 (83.2–90.2)	5.0 (3.8–6.6)	0.4 (0.3–0.4)
≥200	44.8 (40.8–49.0)	95.6 (93.0–97.2)	10.2 (6.3–16.6)	0.5 (0.5–0.6)

CRP, C-reactive protein; LR, likelihood ratio.