Table 2.
Univariate and multivariate Cox regression analysis in relation to 30-day mortality after postoperative ICU admission.
| Variable | Univariate Analysis | Multivariate Analysis | ||
|---|---|---|---|---|
| Hazard Ratio (95% CI) | p-Value | Hazard Ratio (95% CI) | p-Value | |
| Gender: male (vs. female) | 1.05 (0.90–1.21) | 0.556 | - | - |
| Age | 1.02 (1.02–1.03) | <0.001 | 1.02 (1.01–1.02) | <0.001 |
| Body mass index (kg m–2) | 0.94 (0.92–0.95) | <0.001 | 0.97 (0.95–0.98) | <0.001 |
| - <18.5 vs. 18.5–25.0 | 1.61 (1.30–2.00) | <0.001 | 1.29 (1.03–1.61) | 0.024 |
| - >25 vs. 18.5–25.0 | 0.72 (0.60–0.86) | <0.001 | 0.84 (0.70–1.00) | 0.050 |
| Operation time (h) | 0.96 (0.93–1.00) | 0.007 | 0.96 (0.93–0.98) | 0.003 |
| Emergency operation | 1.86 (1.55–2.25) | <0.001 | 1.32 (1.08–1.62) | 0.007 |
| APACHE II | 1.10 (1.09–1.11) | <0.001 | - | - |
| ASA classification | ||||
| - I | 1 | - | 1 | - |
| - II | 0.87 (0.66–1.16) | 0.345 | 0.86 (0.64–1.15) | 0.309 |
| - III | 1.58 (1.21–2.06) | 0.001 | 1.12 (0.85–1.47) | 0.439 |
| - IV + V + VI | 3.50 (2.60–4.71) | <0.001 | 2.03 (1.50–2.76) | <0.001 |
| Blood urea nitrogen (mg dL–1) (>20 vs. ≤20) | 3.66 (3.17–4.22) | <0.001 | 1.55 (1.29–1.87) | <0.001 |
| CRP (mg L–1) (>10 vs. ≤10) | 2.19 (1.80–2.66) | <0.001 | - | - |
| Creatinine (mg dL–1) (>1.3 vs. ≤1.3) | 3.94 (3.40–4.56) | <0.001 | 1.72 (1.43–2.08) | <0.001 |
| AST (IU L–1) (>40 vs. ≤40) | 2.59 (2.25–3.00) | <0.001 | 1.56 (1.30–1.88) | <0.001 |
| ALT (IU L–1) (>40 vs. ≤40) | 2.25 (1.93–2.63) | <0.001 | 1.38 (1.13–1.68) | 0.001 |
| Hemoglobin (g dL–1) (<7 vs. ≥7) | 4.62 (3.28–6.52) | <0.001 | 1.96 (1.33–2.89) | 0.001 |
| Platelet count (103 uL–1) (<100 vs. ≥100) | 3.15 (2.69–3.69) | <0.001 | 2.10 (1.76–2.49) | <0.001 |
| White blood cell (103 uL–1) | ||||
| - <4 vs. 4–10 | 2.93 (2.23–3.85) | <0.001 | 1.80 (1.35–2.41) | <0.001 |
| - >10 vs. 4–10 | 1.21 (1.04–1.41) | 0.016 | 1.13 (0.96–1.33) | 0.132 |
| Serum sodium (mmol L–1) | ||||
| - <135 vs. 135–145 | 2.58 (2.18–3.05) | <0.001 | 1.67 (1.39–2.00) | <0.001 |
| - >145 vs. 135–145 | 4.55 (3.69–5.61) | <0.001 | 2.54 (2.02–3.19) | <0.001 |
| Serum potassium (mEq L–1) | ||||
| - <3.5 vs. 3.5–5 | 1.80 (1.49–2.18) | <0.001 | 1.33 (1.09–1.63) | 0.005 |
| - >5 vs. 3.5–5 | 4.34 (3.44–5.47) | <0.001 | 2.22 (1.73–2.85) | <0.001 |
| History of hypertension | 1.54 (1.26–1.87) | <0.001 | 1.15 (0.90–1.46) | 0.258 |
| History of diabetes mellitus | 1.47 (1.12–1.93) | 0.006 | 1.24 (0.90–1.70) | 0.184 |
| History of ischemic heart disease | 1.58 (1.25–1.99) | <0.001 | 1.57 (1.20–2.04) | 0.001 |
| Diagnosis of cancer | 1.00 (0.86–1.17) | 0.972 | - | - |
| CRP/albumin (dichotomized) | ||||
| - ≤1.75 | 1 | - | 1 | - |
| - >1.75 | 2.14 (1.85–2.47) | <0.001 | 1.30 (1.11–1.53) | 0.001 |
| CRP/albumin (continuous) * | 1.08 (1.01–1.08) | <0.001 | 1.07 (1.05–1.09) | <0.001 |
HR of CRP/albumin (continuous) * was a value from another Cox proportional Hazard model without CRP/albumin (dichotomized). ICU, intensive care unit; BMI, body mass index; APACHE, Acute Physiology and Chronic Health Evaluation; OBGY, obstetric and gynecologic; OPH, ophthalmic; ENT, ear-nose-throat; DT, dental; ASA, American Society of Anesthesiologists; CRP, C-reactive protein; AST, aspartate aminotransferase; ALT, alanine aminotransferase.