Performance parameters of low-risk criteria for detecting SI among well-appearing infants
| Infants classified high risk, n/ total (%) | Prevalence of SI among high risk infants, n/ total (%) | Infants classified low risk n/total (%) | Prevalence of SI among low risk infants n/total (%) | Sensitivity % (95% CI) | Specificity (%) (95% CI) | PPV (95% CI) | NPV (95% CI) | Positive likelihood ratio (95% CI) | Negative likelihood ratio (95% CI) | |
| RC | 705/798 (88.3) | 314/705 (44.5) | 93/798 (11.6) | 8/84 (9.5) | 96.0 (93.0 to 98.0) | 15.7 (12.7 to 19.1) | 37.5 (36.4 to 38.5) | 88.2 (80.2 to 93.2) | 1.14 (1.1 to 1.2) | 0.22 (0.1 to 0.5) |
| PC | 542/603 (89.9) | 276/542 (50.9) | 61/603 (10.1) | 3/61 (4.9) | 94.6 (91.0 to 97.1) | 13.3 (10.0 to 17.2) | 42.3 (41.0 to 43.5) | 78.7 (67.2 to 87.0) | 1.09 (1.0 to 1.1) | 0.5 (0.1 to 1.8) |
| BC | 314/604 (52.0) | 206/314 (65.6) | 290/604 (48.0) | 74/290 (25.5) | 78.2 (72.5 to 83.2) | 65.7 (60.1 to 70.5) | 60.5 (56.7 to 64.2) | 81.7 (77.7 to 85.2) | 2.28 (1.8 to 2.4) | 0.4 (0.3 to 0.5) |
BC, Boston Criteria; NPV, negative predictive value; PC, Philadelphia Criteria; PPV, positive predictive value; RC, Rochester Criteria; SI, serious illness.