Table 3.
Performance metrics for the CCEDRRN COVID-19 Infection Score for ruling in or ruling out SARS-CoV-2 infection at different score cut-off values in the validation cohort
| Score cut-off | n (%) |
Sensitivity
(%, 95% CI) |
Specificity
(%, 95% CI) |
LR+ | LR− |
COVID+
n (%) |
| Rule out: | ||||||
| ≤−2 | 17 (0.3) | 100 (98.4 to 100) | 0.3 (0.2 to 0.5) | 1 | NA | 0 (0) |
| ≤−1 | 310 (5.2) | 99.6 (97.6 to 100) | 5.4 (4.9 to 6.1) | 1.1 | 0.1 | 1 (0.3) |
| ≤0 | 1863 (31.5) | 94.3 (90.4 to 96.9) | 32.5 (31.3 to 33.7) | 1.4 | 0.2 | 13 (0.7) |
| ≤1 | 3806 (64.3) | 78.9 (73.0 to 84.0) | 66.0 (64.7 to 67.2) | 2.3 | 0.3 | 48 (1.3) |
| ≤2 | 5152 (87.0) | 52.9 (46.2 to 60.0) | 88.6 (87.7 to 89.4) | 4.6 | 0.5 | 107 (2.1) |
| ≤3 | 5748 (97.1) | 20.7 (15.6 to 26.6) | 97.8 (97.4 to 98.1) | 9.3 | 0.8 | 180 (3.1) |
| Rule in: | ||||||
| ≥3 | 770 (13.0) | 52.9 (46.2 to 59.5) | 88.6 (87.7 to 89.4) | 4.6 | 0.5 | 120 (15.6) |
| ≥4 | 174 (2.9) | 20.7 (15.6 to 26.6) | 97.8 (97.4 to 98.1) | 9.3 | 0.8 | 47 (27.0) |
| ≥5 | 44 (0.7) | 7.9 (4.8 to 12.2) | 99.5 (99.3 to 99.7) | 17.4 | 0.9 | 18 (40.9) |
| ≥6 | 6 (0.1) | 0.9 (0.1 to 3.2) | 99.9 (99.8 to 100) | 12.5 | 1 | 2 (33.3) |
| ≥7 | 1 (<0.1) | 0 (0 to 1.6) | 100.0 (99.9 to 100) | NA | 1 | 0 (0) |
CCEDRRN, Canadian COVID-19 Emergency Department Rapid Response Network; LR+, positive likelihood ratio; LR−, negative likelihood ratio.