| Time from swab screening to sampling for culture; test characteristic (95% CI)* | Enterococcus species | |||||
|---|---|---|---|---|---|---|
| Test characteristic | Overall | Immediate (0-48 h) | Recent (48 h-14 d) | Remote (> 14 d) | E. faecium | E. faecalis |
| No. of true positives | 7 | 2 | 2 | 3 | 7 | 0 |
| No. of true negatives | 466 | 73 | 182 | 211 | 127 | 339 |
| No. of false positives | 12 | 1 | 5 | 6 | 4 | 8 |
| No. of false negatives | 3 | 0 | 1 | 2 | 3 | 0 |
| Sensitivity, % | 70 (35-93) | 100 (16-100) | 67 (9-99) | 60 (15-95) | 70 (35-93) | NA |
| Specificity, % | 97 (96-99) | 99 (93-100) | 97 (94-99) | 97 (94-99) | 97 (92-99) | 98 (NA) |
| Positive predictive value, % | 37 (16-62) | 67 (9-99) | 29 (3.7-57) | 33 (7.5-70) | 64 (31-89) | 0 (NA) |
| Negative predictive value, % | 99 (98-100) | 100 (95-100) | 100 (97-100) | 99 (97-100) | 98 (93-100) | 100 (NA) |
| Positive likelihood ratio | 28 (14-56) | 74 (11-518) | 25 (7.7-81) | 22 (7.5-63) | 23 (8.1-65) | NA |
| Negative likelihood ratio | 0.31 (0.12-0.79) | 0 (0-NA) | 0.34 (0.069-1.7) | 0.41 (0.14-1.2) | 0.31 (0.12-0.80) | NA |
| Area under ROC curve | 0.84 (0.69-0.99) | 0.99 (0.98-1.0) | 0.82 (0.49-1.0) | 0.79 (0.55-1.0) | 0.84 (0.68-0.99) | NA |
Note: CI = confidence interval, NA = not available, ROC = receiver operating characteristic, VRE = vancomycin-resistant Enterococcus.
*Except where indicated otherwise.