TABLE 3

Sensitivity and Specificity of Individual and Aggregate Components of the Urinalysis

Urinalysis ComponentSensitivitya (95% CI)Specificity (95% CI) n = 115
Individual components
 Any LE, “trace” included97.6 (94.5–99.2)93.9 (87.9–97.5)
 Any LE, “trace” categorized as negative95.7 (92.0–98.0)97.4 (92.5–99.5)
 + for nitrites39.5 (33.3–46)100 (96.8–100)
 Pyuria, >3 WBC/HPF96 (92.5–98.1)91.3 (84.6–95.6)
 Pyuria, >10 WBC/HPF80.7 (74.9–85.7)97.4 (92.6–99.5)
 Any bacteria92 (87.3–95.4)66.1 (56.7–74.7)
Aggregate componentsa
 Nitrites or LE, n = 20997.6 (95.5–99.7)93.9 (87.8–97.5)
 Pyuria >3 WBC/HPF or any bacteriuria, n = 19798.3 (95.2–99.7)63.5 (54–72.3)
 Pyuria >10 WBC/HPF or any bacteriuria, n = 19797 (94.5–99.4)65.2 (55.8–73.9)
 Pyuria >3 WBC/HPF or any LE, n = 20399.5 (98.5–100)87.8 (80.4–93.2)
 Any positive UA (pyuria ≥3 WBC/HPF), infants with complete UA results only, n = 17899.4 (98.3–100)60 (50.4–69)
  Infants ≤30 d, n = 72100 (95–199)53.1 (38.3–67.5)
  Infants 31–92 d, n = 10699.1 (94.9–100)65.2 (52.4–76.5)
 Any positive UA (pyuria ≥3 WBC/HPF), entire sample, n = 24598.4 (96.8–100)60 (50.4–69)
  Infants ≤ 30 d, n = 10199 (94.6–100)53.1 (38.3–67.5)
  Infants 31–92 d, n = 14497.9 (94–99.6)65.2 (52.4–76.5)
  • a Analyses performed for infants in whom results for each component were reported. The “n’s” refer to the denominator for the sensitivity calculations.