Table 4.
Procalcitonin cutoffs (0.5 and 2.0 μg/L) for risk prediction in different clinical settings and in various acute respiratory infection subgroups a
| Cutoff (μg/L) | 0.5 μg/L | 2.0 μg/L | ||||||
|---|---|---|---|---|---|---|---|---|
| Sensitivity (%) | Specificity (%) | PPV (%) | NPV (%) | Sensitivity (%) | Specificity (%) | PPV (%) | NPV (%) | |
| (95% CI) | (95% CI) | (95% CI) | (95% CI) | (95% CI) | (95% CI) | (95% CI) | (95% CI) | |
| PC | ||||||||
| Treatment failure | 1.86 (0.69, 4.00) | 98.7 (97.5, 99.4) | 40.0 (16.3, 67.7) | 68.0 (65.0, 70.9) | NA | NA | NA | NA |
| ED | ||||||||
| Treatment failure | 50.2 (45.3, 55.2) | 68.6 (66.6, 70.6) | 23.1 (20.3, 26.0) | 88.0 (86.4, 89.6) | 27.6 (23.3, 32.2) | 85.9 (84.4, 87.4) | 26.8 (22.7, 31.3) | 86.4 (84.9, 87.8) |
| Mortality | 52.5 (43.2, 61.7) | 66.5 (64.6, 68.4) | 7.05 (5.46, 8.94) | 96.7 (95.7, 97.5) | 28.3 (20.5, 37.3) | 84.4 (82.9, 85.8) | 8.08 (5.66, 11.1) | 96.1 (95.1, 96.8) |
| ICU | ||||||||
| Mortality | 67.2 (58.2, 75.3) | 30.8 (26.2, 35.7) | 24.2 (19.8, 29.1) | 74.1 (66.5, 80.7) | 37.6 (29.1, 46.7) | 58.2 (53.0, 63.2) | 22.8 (17.3, 29.2) | 73.9 (68.5, 78.8) |
| Total lower ARI | ||||||||
| Treatment failure | 44.9 (41.0, 48.8) | 66.4 (64.7, 68.2) | 23.5 (21.2, 26.0) | 84.0 (82.4, 85.5) | 24.4 (21.1, 27.9) | 83.4 (82.0, 84.8) | 25.3 (21.9, 28.9) | 82.8 (81.3, 84.1) |
| Mortality | 61.2 (54.7, 67.4) | 66.2 (64.5, 67.8) | 11.7 (9.97, 13.6) | 95.9 (95.0, 96.7) | 33.8 (27.8, 40.2) | 83.1 (81.8, 84.4) | 12.8 (10.3, 15.7) | 94.5 (93.6, 95.3) |
| Bronchitis | ||||||||
| Treatment failure | 0.95 (0.02, 5.19) | 96.0 (93.7, 97.7) | 5.56 (0.14, 27.3) | 79.7 (75.9, 83.1) | NA | NA | NA | NA |
| Mortality | 0.00 (0.00, 84.2) | 96.6 (94.7, 98.0) | 0.00 (0.00, 18.5) | 99.6 (98.6, 100) | NA | NA | NA | NA |
| ECOPD | ||||||||
| Treatment failure | 11.3 (5.28, 20.3) | 93.8 (91.3, 95.8) | 22.5 (10.8, 38.5) | 86.9 (83.8, 89.6) | 2.50 (0.30, 8.74) | 98.8 (97.4, 99.6) | 25.0 (3.19, 65.1) | 86.4 (83.3, 89.1) |
| Mortality | 29.4 (10.3, 56.0) | 93.8 (91.5, 95.6) | 12.5 (4.19, 26.8) | 97.8 (96.2, 98.9) | 5.88 (0.15, 28.7) | 98.8 (97.5, 99.5) | 12.5 (0.32, 52.7) | 97.2 (95.5, 98.4) |
| CAP | ||||||||
| Treatment failure | 62.5 (57.7, 67.1) | 54.1 (51.6, 56.6) | 27.0 (24.2, 29.9) | 84.2 (81.8, 86.4) | 34.9 (30.4, 39.7) | 77.7 (75.5, 79.7) | 29.8 (25.8, 34.0) | 81.5 (79.4, 83.4) |
| Mortality | 64.0 (56.8, 70.7) | 52.2 (49.8, 54.5) | 12.8 (10.8, 15.1) | 92.9 (91.2, 94.4) | 36.0 (29.3, 43.2) | 76.2 (74.1, 78.1) | 14.3 (11.3, 17.7) | 91.5 (90.0, 92.9) |
aARI, Acute respiratory tract infection; CAP, Community-acquired pneumonia; CI, Confidence interval; ECOPD, Exacerbated chronic obstructive pulmonary disease; ED, Emergency department; ICU, Intensive care unit; NA, Not applicable due to small sample size; NPV, Negative predictive value; PC, Primary care; PCT, Procalcitonin; PPV, Positive predictive value.