TABLE 3

Multivariate logistic regression analysis of factors associated with tissue culture positivity

FactorUnivariate analysisMultivariate analysisa
OR (95% CI)P valueaOR (95% CI)P value
Sex
    Male1.00
    Female0.37 (0.13–1.09)0.0720.286
Age of ≥65 yr0.89 (0.31–2.53)0.8250.374
Fever1.11 (0.38–3.28)0.8490.533
Motor weakness1.09 (0.28–4.25)0.9050.990
Sepsis2.46 (0.80–7.63)0.1180.405
L-spine involved0.51 (0.11–2.37)0.3920.186
No. of involved vertebral bodies
    1 or 2 levels1.00
    ≥3 levels1.31 (0.41–4.27)0.6490.619
Duration of prior antibiotic exposure0.97 (0.92–1.02)0.1760.783
Prior antibiotic exposureb
    Cephalosporin0.76 (0.23–2.47)0.6490.842
    Quinolone0.33 (0.08–1.40)0.1330.476
    Glycopeptide1.08 (0.20–5.85)0.9290.905
Antibiotic-free period0.80 (0.66–0.96)0.0150.407
Presence of abscess1.83 (0.56–5.96)0.3140.550
Initial CRP levelc1.15 (1.06–1.25)0.0011.18 (1.07–1.29)<0.001
Tissue biopsy method
    Needle1.00
    Open surgery3.00 (0.69–13.02)0.1426.33 (1.12–35.86)0.037
  • a The aORs were calculated with a stepwise forward selection logistic regression model.

  • b Cephalosporin, glycopeptide, and quinolone were not simultaneously included in the multivariate model.

  • c Because the CRP level and WBC count showed a significant correlation (Pearson correlation coefficient of 0.549, P < 0.001), we included only the CRP level in the multivariate analysis model.