Table 2: Univariate analysis and multiple regression analysis of associations between selected variables and 30-day mortality.

Univariate analysis Multiple regression analysisa
OR (95% CI) P value OR (95% CI) P value
Age 1.06 (1.03-1.09) < 0.001 1.06 (1.02-1.09) 0.001
Male sex 0.65 (0.45-0.96) 0.028 0.74 (0.46-1.17) 0.19
Charlson index 1.12 (1.03-1.21) 0.008 1.08 (0.98-1.20) 0.11
Pitt severity score 1.78 (1.57-2.02) < 0.001 1.84 (1.60-2.11) < 0.001
Site of sepsis origin 0.002 0.002
UTI 2.75 (1.24-6.12) 0.01 3.11 (1.22-7.96)
RTI 1.4 (0.61-3.21) 0.43 1.63 (0.62-4.30)
Other 3.05 (1.17-7.91) 0.02 3.56 (1.17-10.87)
Unknown 1 1 1
Non-CRB vs. CRB 1.54 (0.98-2.4) 0.053 1.11 (0.64-1.90) 0.71
Aetiology of sepsis 0.47 0.45
Identified, ESBL-E 0.8 (0.5-1.28) 0.34 1.05 (0.55-2.00)
Identified, not ESBL-E 1.06 (0.69-1.64) 0.78 1.37 (0.81-2.31)
Unidentified 1 1 1

OR: odds ratio; CI: confidence interval; RTI: respiratory tract infection; UTI: urinary tract infection; CRB: carbapenem; ESBL-E: extended-spectrum β-lactamase-producing Enterobacteriaceae.
aThe value of the intercept in the multivariable model was -7.90.