Table 7.
Post-test probability of significant symptoms with a positive (LR 4.42) or negative dipstick (LR 0.53) test for nitrites [23]
| Symptom | Reference standard | Pre-test probability (95%CI) (%) |
Post-test probability (95% CI) (LR+) |
Post-test probability (95% CI) (LR-) |
|---|---|---|---|---|
| Dysuria | 102 CFU/ml | 71.0 (70.0-71.0) | 91.5 (91.2-92.0) | 56.5 (55.3-56.5) |
| 103 CFU/ml | 62.3 (61.0-63.6) | 88.0 (87.4-88.5) | 46.7 (45.3-48.1) | |
| 105 CFU/ml | 51.1 (49.5-52.8) | 82.2 (81.2-83.2) | 35.6 (34.2-37.2) | |
| Frequency | 102 CFU/ml | 67.8 (67.0-68.5) | 90.3 (90.0-91.0) | 52.7 (51.8-53.5) |
| 103 CFU/ml | 58.6 (57.5-59.5) | 86.2 (85.7-87.0) | 42.9 (41.8-43.8) | |
| 105 CFU/ml | 47.8 (46.7-49.0) | 80.2 (79.5-81.0) | 32.7 (31.7-33.7) | |
| Hematuria | 102 CFU/ml | 75.8 (70.9-80.1) | 93.3 (91.5-95.0) | 62.4 (56.4-68.1) |
| 103 CFU/ml | 67.4 (60.6-73.6) | 90.1 (87.2-92.5) | 52.3 (44.9-59.6) | |
| Nocturia | 102 CFU/ml | 69.4 (67.3-71.3) | 91.0 (90.1-92.0) | 54.6 (52.1-56.8) |
| 103 CFU/ml | 60.8 (58.4-63.3) | 87.3 (86.1-88.4) | 45.1 (42.7-47.8) | |
| Urgency | 102 CFU/ml | 69.8 (68.5-71.1) | 91.0 (90.6-91.6) | 55.1 (53.5-56.6) |
| 103 CFU/ml | 61.7 (59.9-63.6) | 87.7 (86.8-88.5) | 46.1 (44.2-48.1) | |
| 105 CFU/ml | 49.1 (47.1-51.1) | 81.0 (79.7-82.2) | 33.8 (32.1-35.6) | |
| Vaginal discharge | 102 CFU/ml | 54.1 (48.3 - 59.9) | 84.0 (80.5-86.8) | 38.4 (33.1-44.2) |