TABLE 3.
Sensitivity (95% CI) % |
Specificity (95% CI) % |
PPV (95% CI) % |
NPV (95% CI) % |
|
Sputum colour grade ≥2 | 93.3 (86.6–97.3) | 46.5 (41.4–51.6) | 32.2 (29.9–34.6) | 96.2 (92.5–98.1) |
Sputum colour grade 3/4 only | 58.7 (48.6–68.2) | 79.1 (73.8–83.7) | 51.3 (33.3–58.2) | 83.6 (80.1–86.6) |
P. aeruginosa patients only | 37.5 (28.2–47.5) | 92.4 (88.6–95.3) | 65.0 (53.5–75.0) | 79.8 (77.2–82.1) |
P. aeruginosa+grade 3/4 sputum and a history of ≥2 exacerbations per year | 24.0 (16.2–33.4) | 98.7 (97.0–99.6) | 83.3 (66.2–92.7) | 82.6 (81.0–84.1) |
Sputum colour grade ≥2 and ≥2 exacerbations per year | 65.4 (55.4–74.5) | 76.1 (71.5–80.3) | 42.8 (37.3–48.4) | 89.0 (86.0–91.3) |
Sputum colour grade ≥2, MRC dyspnoea score ≥3, ≥3 lobes involved on CT and ≥2 exacerbations per year | 37.5 (28.2–47.5) | 91.6 (88.4–94.2) | 54.9 (44.6–64.8) | 84.3 (82.2–86.2) |
≥3 exacerbations per year, ≥2 lobes involved on CT and infection with any organism (including P. aeruginosa) | 16.4 (9.8–24.9) | 91.3 (88.1–94.0) | 34.0 (23.0–47.0) | 80.0 (78.5–81.4) |
PPV: positive predictive value; NPV: negative predictive value; P. aeruginosa: Pseudomonas aeruginosa; MRC: Medical Research Council; CT: computed tomography.