Table 2.
Logistic regression models for predicting 30-day mortality.
| Variable | Model 1—entire sample | Model 2—diabetics with general surgery subgroup | Model 3—diabetics with vascular surgery subgroup |
|---|---|---|---|
| Model R-square | |||
| 0.333 | 0.300 | 0.165 | |
| Odds ratio (95% CI) | Odds ratio (95% CI) | Odds ratio (95% CI) | |
| Diabetes | |||
| Nondiabetic | Reference category | ||
| Diabetic—oral | 0.78 (0.70, 0.86)* | Reference category | Reference category |
| Diabetic—insulin | 0.83 (0.75, 0.92)* | 1.18 (1.00, 1.39) | 1.06 (0.83, 1.35) |
| Anesthesia technique | |||
| General | Reference category | Reference category | Reference category |
| Epidural | 0.46 (0.24, 0.91)* | 0.00 (0.00, α) | 0.85 (0.34, 2.11) |
| Spinal | 0.87 (0.68, 1.09) | 0.25 (0.06, 1.01) | 1.25 (0.85, 1.82) |
| Regional | 0.48 (0.30, 0.76)* | 1.08 (0.14, 8.16) | 0.29 (0.11, 0.79) |
| Local | 0.43 (0.19, 0.95)* | 0.00 (0.00, α) | 0.09 (0.003, 2.33) |
| Monitored anesthesia care | 0.78 (0.64, 0.96)* | 0.97 (0.62, 1.51) | 0.96 (0.62, 1.49) |
| Other | 1.06 (0.46, 2.44) | 1.14 (0.15, 8.69) | 0.00 (0.00, α) |
| None | 3.60 (1.03, 12.6)* | 0.00 (0.00, α) | 0.00 (0.00, α) |
| Surgical specialty: vascular | 1.57 (1.42, 1.72)* | ||
| Male gender | 0.99 (0.92, 1.06) | 1.15 (0.98, 1.35) | 0.92 (0.75, 1.16) |
| Ventilator dependent | 2.19 (1.93, 2.49)* | 2.13 (1.63, 2.79)* | 3.54 (2.13, 5.88)* |
| COPD | 1.61 (1.47, 1.76)* | 1.54 (1.26, 1.88)* | 1.54 (1.17, 2.02)* |
| Cardiac risk factors | 1.57 (1.43, 1.72)* | 1.18 (0.91, 1.152) | 1.49 (0.87, 2.53) |
| On dialysis | 1.39 (1.24, 1.56)* | 1.85 (1.46, 2.35)* | 1.88 (1.46, 2.42)* |
| Steroid use | 1.31 (1.16, 1.48)* | 1.29 (0.98, 1.70) | 1.15 (0.73, 1.8) |
| 10% weight loss | 2.81 (2.45, 3.22)* | 2.73 (1.98, 3.77)* | 2.25 (1.24, 4.08)* |
| Sepsis | |||
| None | Reference category | Reference category | Reference category |
| Sepsis | 2.62 (2.32, 2.96)* | 2.49 (1.92, 3.23)* | 1.84 (1.26, 2.68)* |
| Septic shock | 3.39 (2.93, 3.94)* | 3.89 (2.85, 5.34)* | 3.42 (1.91, 6.14)* |
| SIRS | 2.30 (2.08, 2.55)* | 2.13 (1.67, 2.73)* | 1.80 (1.29, 2.53)* |
| Emergent case | 2.33 (2.15, 2.53)* | 2.09 (1.73, 2.53)* | 2.35 (1.78, 3.11)* |
| ASA class | |||
| No ASA class assigned | Reference category | 0.00 (0.00, α) | Reference category |
| No disturbance | 0. 44 (0.014, 0.14)* | 0.00 (0.00, α) | 0.00 (0.00, α) |
| Mild disturbance | 0.20 (0.08, 0.49)* | 0.06 (0.033, 0.107)* | 0.21 (0.005, 8.64)* |
| Severe disturbance | 1.53 (0.62, 3.78) | 0.20 (0.13, 0.32)* | 0.41 (0.11, 15.2)* |
| Life threatening | 5.40 (2.19, 13.2)* | 0.64 (0.42, 0.99)* | 0.89 (0.024, 33.0)* |
| Moribund | 13.6 (5.44, 33.9)* | Reference category** | 5.37 (0.13, 217.5)* |
| Wound classification | |||
| Clean | Reference category | Reference category | Reference category |
| Clean/contaminated | 2.01 (1.82, 2.22)* | 2.40 (1.87, 3.09)* | 2.03 (1.39, 2.96)* |
| Contaminated | 1.88 (1.66, 2.14)* | 2.45 (1.80, 3.33)* | 1.34 (0.89, 2.02) |
| Dirty/infected | 1.78 (1.58, 1.99)* | 2.37 (1.76, 3.18)* | 0.99 (0.71, 1.40) |
Values expressed as odds ratios (95% confidence intervals x, y). *Significance at P < 0.05. **Moribund category is used as the reference category as there were no cases designated as “not assigned” or “no disturbance” and odds ratios could not be calculated in reference to these categories. COPD: chronic obstructive pulmonary disease, ASA: American Society of Anesthesiologists, SIRS: systemic inflammatory response syndrome, and CI: confidence interval.