Table 4. Analysis of diagnostic factors at presentation for N.meningitidis, S.pneumoniae, H.influenzae, and Others.
| Diagnostic Factors | N.meningitidis | S. pneumoniae | H. influenzae | Other | ||||||||
| RR 95%CI | P | PPV 95%CI | RR 95%CI | P | PPV 95%CI | RR 95%CI | P | PPV 95%CI | RR 95%CI | P | PPV 95%CI | |
| CSF Fluid Analysis at Presentation | ||||||||||||
| Positive CSF culture | 0.72 0.67–0.78 | <0.001 | 58.3 55.1–61.4 | 1.98 1.25–3.12 | 0.002 | 15.2 13.0–17.7 | 2.63 1.72–4.03 | <0.001 | 22.4 19.2–25.1 | 1.28 0.61–2.70 | 0.516 | 4.1 3.0–5.6 |
| Positive Gram stain | 0.78 0.71–0.85 | <0.001 | 57.5 54.0–61.0 | 2.61 1.74–3.92 | <0.001 | 17.9 15.3–20.8 | 1.64 1.23–2.20 | 0.001 | 22.1 19.2–25.2 | 0.44 0.24–0.81 | 0.006 | 2.6 1.6–4.0 |
| CSF WBC≤100/µL | 1.47 1.36–1.58 | <0.001 | 85.9 80.2–90.4 | 0.54 0.33–0.88 | 0.005 | 8.1 4.7–12.8 | 0.07 0.02–0.21 | <0.001 | 1.5 0.3–4.4 | 1.12 0.56–2.25 | 0.756 | 4.5 2.1–8.5 |
| CSF WBC≤1000/µL | 1.20 1.10–1.30 | <0.001 | 70.4 65.8–74.6 | 1.17 0.89–1.55 | 0.271 | 15.4 12.2–19.2 | 0.34 0.25–0.48 | <0.001 | 8.5 6.1–11.6 | 1.72 1.02–2.89 | 0.041 | 5.7 3.8–8.5 |
| CSF Glu<40 mg/dL | 0.71 0.66–0.78 | <0.001 | 53.6 49.8–57.3 | 1.19 0.89–1.59 | 0.238 | 14.4 12.0–17.3 | 2.80 2.11–3.72 | <0.001 | 27.3 24.1–30.8 | 1.48 0.83–2.63 | 0.179 | 4.6 3.3–6.5 |
| CSF Protein>100 mg/dL | 0.81 0.75–0.88 | <0.001 | 57.0 53.2–60.7 | 1.35 1.01–1.81 | 0.044 | 15.2 12.6–18.1 | 1.53 1.20–1.94 | <0.001 | 23.2 20.2–26.6 | 1.42 0.80–2.49 | 0.226 | 4.6 3.2–6.5 |
| ≥65% neutrophils in CSF | 1.02 0.8–1.21 | 0.774 | 60.1 56.9–63.2 | 0.89 0.55–1.43 | 0.624 | 13.6 11.6–16.0 | 1.22 0.80–1.87 | 0.338 | 22.4 19.8–25.1 | 0.51 0.24–1.06 | 0.067 | 3.9 2.8–5.4 |
| Peripheral Blood Analysis at Presentation | ||||||||||||
| Positive blood culture | 0.85 0.75–0.95 | 0.004 | 55.9 49.9–61.8 | 1.30 0.94–1.81 | 0.117 | 16.8 12.6–21.8 | 1.10 0.83–1.47 | 0.499 | 20.1 15.5–25.3 | 2.45 1.33–4.52 | 0.003 | 7.2 4.4–10.9 |
| Peripheral WBC<5000/µL | 0.84 0.69–1.02 | 0.052 | 53.9 43.0–64.6 | 0.73 0.39–1.37 | 0.315 | 10.1 4.7–18.3 | 1.41 0.97–2.05 | 0.079 | 25.8 17.1–36.2 | 2.81 1.41–5.58 | 0.008 | 10.1 4.7–18.3 |
| Peripheral WBC>15000/µL | 1.07 0.99–1.17 | 0.095 | 66.0 61.9–69.9 | 1.55 1.17–2.04 | 0.002 | 17.0 14.0–20.5 | 0.66 0.56–0.85 | 0.001 | 14.7 11.9–17.9 | 0.43 0.23–0.79 | 0.005 | 2.3 1.3–4.0 |
| Absolute blood neutrophil count<1000/µL | 0.94 0.62–1.43 | 0.771 | 60.0 32.3–83.7 | 0.49 0.07–3.30 | 0.708 | 6.7 0.2–31.9 | 0.70 0.19–2.57 | 0.750 | 13.3 1.7–40.5 | 5.13 1.79–14.68 | 0.021 | 20.0 4.3–48.1 |