Table 4.

Overall sensitivity, specificity, positive, and negative predictive values (PPV and NPV) [95% CI].

Germ	EPs (n = 105)		NEPs (n = 30)		BAL-Group (n = 39)
	Nose swab	Cough swab	Nose swab	Induced sample	Nose swab	Cough swab	Induced samplea
Pa	n = 44		n = 2		n = 14
Sensitivity	20.5% [9.8–35.3]	86.7% [73.2–95.0]	N.A.	N.A.	7.1% [0.2–33.9]	85.7% [57.2–98.2]	100.0% [71.5–100.0]
Specificity	100.0% [94.1–100.0]	98.3% [91.1–100.0]	N.A.	N.A.	100.0% [86.3–100.0]	100.0% [86.3–100.0]	100.0% [71.5–100.0]
PPV	100.0% [–]	97.5% [84.8–99.6]	N.A.	N.A.	100.0% [–]	100.0% [–]	100.0% [–]
NPV	63.5% [60.0–66.9]	90.8% [82.4–95.4]	N.A.	N.A.	65.8% [62.5–69.0]	92.6% [77.6–97.8]	100.0% [–]
Sa	n = 69		n = 17		n = 16
Sensitivity	58.0% [45.5–69.8]	89.9% [80.2–95.8]	47.1% [23.0–72.2]	76.7% [50.1–93.2]	20.0% [4.3–48.1]	75.0% [47.6–92.7]	88.9% [51.8–99.7]
Specificity	83.3% [67.2–93.6]	86.1% [70.5–95.3]	84.6% [54.6–98.1]	92.3% [64.0–99.8]	95.8% [78.9–99.9]	100.0% [85.2–100.0]	100.0% [75.3–100.0]
PPV	87.0% [75.8–93.4]	92.5% [84.6–96.6]	80.0% [50.4–94.0]	92.9% [66.0–98.9]	75.0% [25.5–96.3]	100.0% [–]	100.0% [–]
NPV	50.9% [43.1–58.6]	81.8% [68.4–90.1]	55.0% [42.5–66.9]	75.0% [55.7–87.8]	65.7% [59.5–71.4]	85.2% [71.1–93.1]	92.9% [67.2–98.8]
Hi	n = 15		n = 3		n = 5
Sensitivity	20.0% [4.3–48.1]	40.0% [16.3–67.7]	N.A.	N.A.	20.0% [0.5–71.6]	80.0% [28.4–99.5]	0.0% [0.0–97.5]
Specificity	98.9% [94.0–99.9]	97.8% [92.2–99.7]	N.A.	N.A.	100.0% [89.7–100.0]	97.06% [84.7–99.9]	100.0% [83.9–100.0]
PPV	75.0% [25.0–96.4]	75.0% [40.0–93.1]	N.A.	N.A.	100.0% [–]	80.0% [35.6–96.7]	- [–]
NPV	88.1% [85.2–90.5]	90.7% [86.6–93.7]	N.A.	N.A.	89.5% [84.6–93.0]	97.1% [85.1–99.5]	95.5% [95.5–95.5]
Other Gram–	n = 38		n = 17		n = 14
Sensitivity	6.3% [0.8–20.8]	66.7% [48.2–82.0]	0.0% [0.0–30.9]	80.0% [44.4–97.5]	14.3% [0.4–57.9]	42.9% [9.9–51.6]	66.7% [9.4–99.2]
Specificity	96.2% [89.3–99.2]	94.9% [87.4–98.6]	84.6% [65.1–95.6]	84.6% [65.1–95.6]	80.6% [64.0–91.8]	97.3% [85.8–99.9]	100.0% [84.6–100.0]
PPV	40.0% [10.5–79.2]	84.6% [67.3–93.6]	– [–]	66.7% [43.5–83.8]	12.5% [2.0–49.7]	75.0% [26.6–96.1]	100.0% [–]
NPV	71.7% [69.6–73.7]	87.1% [80.6–91.6]	68.8% [65.1–72.2]	91.7% [75.9–97.5]	82.9% [77.4–87.2]	90.0% [82.5–94.5]	95.7% [81.6–99.1]

EPs, expectorating patients; NEPs, non-expectorating patients; BAL-group, patients requiring clinically indicated bronchoscopy.

^aOnly 22 induced sputum samples. Pa, Pseudomonas aeruginosa; N.A., not applicable (because of low sample size); Sa, Staphylococcus aureus; Hi, Haemophilus influenzae; Other Gram–, other gram negative organisms (see Table 3).