Table 2—

Univariable and multivariable cox proportional hazard model for various variables

VariablesModel for survival
UnivariableMultivariable
dfChi–squaredHazard ratio (95% CI)p-valuedfChi–squaredHazard ratio (95% CI)p-value
Log10PCT (per IQR increase)166.32.36 (1.92–2.91)<0.00001118.01.79 (1.37–2.34)<0.0001
WBC (per IQR increase)115.71.48 (1.22–1.8)0.0000711.41.14 (0.92–1.43)0.2374
CRP (per IQR increase)110.11.58 (1.19–2.09)0.001451<0.051.01 (0.72–1.41)0.9761
CRB-65352.0<0.00001330.9<0.0001
CRB-65 1/010.25 (2.41–43.58)6.69 (1.56–28.65)
CRB-65 2/031.56 (7.51–132.71)18.92 (4.47–80.04)
CRB-65 3,4/071.46 (15.99–319.43)31.12 (6.79–142.59)
  • df: degrees of freedom; CI: confidence interval; PCT: procalcitonin; IQR: interquartile range; WBC: leukocyte; CRP: C-reactive protein; CRB-65: confusion, respiratory rate ≥30 breaths·min−1, low blood pressure (systolic value <90 mmHg or diastolic value ≤60 mmHg) and age ≥65 yrs.