qSOFA, SIRS, severe sepsis and lactate level: screening performance characteristics for composite outcome
| Criteria | Sensitivity, % (95% CI) | Specificity, % (95% CI) | Negative predictive value, % (95% CI) | Negative likelihood ratio (95% CI) | Positive predictive value, % (95% CI) | Positive likelihood ratio (95% CI) |
| SIRS TP=444 TN=1473 FP=1758 FN=68 | 86.7 (83.5 to 89.5) (98.1 to 99) | 45.6 (43.9 to 47.3) | 95.6 (94.5 to 96.4) | 0.29 (0.23 to 0.36) | 20.2 (19.4 to 20.9) | 1.6 (1.5 to 1.7) |
| Severe sepsis TP=357 TN=2503 FP=728 FN=155 | 69.7 (65.5 to 73.7) | 77.5 (76.0 to 78.9) | 94.2 (93.4 to 94.9) | 0.39 (0.34 to 0.45) | 32.9 (31.0 to 34.8) | 3.1 (2.8 to 3.4) |
| qSOFA≥1 TP=441 TN=1833 FP=1398 FN=71 | 86.1 (82.8 to 89.0) | 56.7 (55.0 to 58.5) | 96.3 (95.4 to 97.0) | 0.24 (0.20 to 0.30) | 24.0 (23.0 to 25.0) | 2.0 (1.9 to 2.1) |
| qSOFA ≥2 TP = 274 TN=2879 FP=352 FN=238 | 53.5 (49.0 to 57.9) | 89.1 (88.0 to 90.2) | 92.4 (91.7 to 93.0) | 0.52 (0.48 to 0.57) | 43.8 (40.7 to 46.9) | 4.9 (4.3 to 5.6) |
| qSOFA ≥3 TP=90 TN=3175 FP=56 FN=422 | 17.6 (14.4 to 21.2) | 98.3 (97.8 to 98.7) | 88.3 (87.8 to 88.7) | 0.84 (0.81 to 0.87) | 61.6 (53.9 to 68.9) | 10.1 (7.4 to 14.0) |
| Lactate ≥2 TP=286 TN=1517 FP=602 FN=179 | 61.5 (56.9 to 66.0) | 71.6 (69.6 to 73.5) | 89.5 (88.3 to 90.5) | 0.54 (0.48 to 0.61) | 32.2 (30.1 to 34.4) | 2.2 (2.0 to 2.4) |
| Lactate ≥4 TP=121 TN=2035 FP=84 FN=344 | 26.0 (22.1 to 30.3) | 96.0 (95.1 to 96.3) | 85.5 (84.9 to 86.2) | 0.77 (0.73 to 0.81) | 59.0 (52.6 to 65.1) | 6.6 (5.1 to 8.5) |
qSOFA, quick sequential organ failure assessment; SIRS, systemic inflammatory response syndrome; FN, false negative; FP, false positive; TN, true negative; TP, true positive.