TABLE 2.
Characteristics of Case Patients and Controls
| Characteristic | Case Patients (N = 135), n (%) | Controls (N = 249), n (%) | P |
|---|---|---|---|
| Demographics | |||
| Age group, d | .01 | ||
| ≤28 | 68 (50.4) | 92 (37.0) | |
| 29–60 | 67 (49.6) | 157 (63.1) | |
| Female sex | 61 (45.2) | 102 (41.0) | .42 |
| Parameters of Rochester criteria | |||
| Low risk | 25 (18.5) | 149 (59.8) | <.001 |
| Previously healthya | 107 (79.3) | 206 (82.7) | .40 |
| Normal urinalysisb | 61 (45.2) | 219 (88.0) | <.001 |
| Peripheral WBC ≥5000 and ≤15 000 | 86 (63.7) | 200 (80.3) | <.001 |
| Normal absolute band countc | 110 (81.5) | 240 (96.4) | <.001 |
| Parameters of modified Philadelphia criteria | |||
| Low risk | 11 (8.1) | 86 (34.5) | <.001 |
| Previously healthya | 107 (79.3) | 206 (82.7) | .40 |
| Normal urinalysisb | 61 (45.2) | 219 (88.0) | <.001 |
| Peripheral WBC ≥5000 and ≤15 000 | 86 (63.7) | 200 (80.3) | <.001 |
| Normal I/T ratiod | 103 (76.3) | 234 (94.0) | <.001 |
a
Gestational age ≥37 wk; no previous ED visit, hospitalization, or evaluation for fever; no previous IBI or treatment with antibiotics; no other significant past medical history.
b
Urine dipstick with no or trace leukocyte esterase, negative nitrites, and urine microscopy, with ≤5 WBCs per HPF or ≤5 WBCs per mm3 on an enhanced urinalysis.
c
Absolute band count ≤1500.
d
Bands-to-total neutrophil ratio <0.2.