Table 3. Univariate analysis of risk factors for being a RT-PCR positive, culture-negative case-patient, using culture positive patients as controls.
| Risk Factor | Cases, No. (%) | Controls, No. (%) | OR | 95% CI | p-value |
| Male gender | 69 (58.5%) | 102 (63.4%) | 0.8 | 0.5-1.3 | 0.41 |
| Age ≥18 years | 59 (50.0%) | 49 (30.6%) | 2.3 | 1.4–3.7 | 0.0012 |
| Hospitalized | 113 (99.1%) | 160 (99.4%) | 0.7 | 0.04–11.4 | 0.81 |
| Race - White | 61 (67.8%) | 66 (55.9%) | Baseline | 0.22 | |
| White vs. Black | 4 (4.4%) | 7 (5.9%) | 0.6 | 0.2–2.2 | |
| White vs. Brown | 25 (27.8%) | 45 (38.1%) | 0.6 | 0.3–1.1 | |
| Antibiotic in CSF | 79 (76.7%) | 25 (17.5%) | 15.5 | 8.3–29.1 | <0.0001 |
| CSF MIC (mm) | 21.0 (7–53) | 21.0 (9–40) | 0.59 | ||
| CSF glucose | 16 (0–101) | 10 (0–610) | 0.06 | ||
| CSF WBC count (cell/mm3) | 4,400 (100–29600) | 1,280 (1–95200) | <0.0001 | ||
| CSF % neutrophils | 89 (60–99) | 86 (0–100) | 0.11 | ||
| CSF protein (xx) | 286.5 (22–4854) | 230 (11–2789) | 0.14 | ||
| Hospital | |||||
| Hospital 10 | 1 (0.9%) | 22 (13.6%) | Baseline | <0.0001 | |
| Hospital 1 vs. 10 | 10 (8.5%) | 22 (13.6%) | 10.0 | 1.2–84.9 | |
| Hospital 2 vs. 10 | 8 (6.8%) | 21 (13.0%) | 8.4 | 0.96–72.9 | |
| Hospital 3 vs. 10 | 19 (16.1%) | 26 (16.1%) | 16.1 | 2.0–129.9 | |
| Hospital 4 vs. 10 | 1 (0.9%) | 2 (1.2%) | 11.0 | 0.5–250.9 | |
| Hospital 5 vs. 10 | 5 (4.2%) | 22 (13.6%) | 5.0 | 0.5–46.4 | |
| Hospital 6 vs. 10 | 8 (6.8%) | 4 (2.5%) | 44.0 | 4.3–454.9 | |
| Hospital 7 vs. 10 | 2 (1.7%) | 5 (3.1%) | 8.8 | 0.7–117.2 | |
| Hospital 8 vs. 10 | 2 (1.7%) | 14 (8.6%) | 3.1 | 0.3–38.0 | |
| Hospital 9 vs. 10 | 4 (3.4%) | 9 (5.6%) | 9.8 | 0.96–99.9 | |
| Hospital 11 vs. 10 | 57 (48.3%) | 13 (8.0%) | 96.5 | 11.9–781.9 | |
| Hospital 12 vs. 10 | 1 (0.9%) | 2 (1.2%) | 11.0 | 0.5–250.9 | |
| Hospital 3, 6, 11 vs. others | 84 (71.2%) | 43 (26.5%) | 6.8 | 4.0–11.6 | <0.0001 |
| Bacterial species | |||||
| N. meningitidis | 91 (77.1%) | 108 (66.7%) | 1.7 | 0.98–2.9 | 0.06 |
| S. pneumoniae | 26 (22.0%) | 50 (30.9%) | 0.6 | 0.4–1.1 | 0.10 |
| H. influenzae | 1 (0.9%) | 5 (3.1%) | 0.3 | 0.03–2.3 | 0.23 |
There were a total of 118 case-patients and 162 controls. For some calculations, denominators differ because of missing data for some patients.
OR, odds ratio; CI, confidence interval; CSF, cerebrospinal fluid; MIC, minimum inhibitory concentration of CSF against strain of Kocuria rhizophila among specimens with detectable antibiotic; WBC, white blood cell.