Table 3: Logistic regression models for predicting 30-day morbidity.

VariableModel 4—entire sampleModel 5—diabetics with general surgery sub-groupModel 6—diabetics with vascular surgery sub-group
Model R-square
0.2250.2040.111
Odds ratio (95% CI)Odds ratio (95% CI)Odds ratio (95% CI)

Diabetes
 NondiabeticReference category
 Diabetic—oral0.96 (0.92, 1.01)Reference categoryReference category
 Diabetic—insulin1.11 (1.06, 1.16)*1.20 (1.12, 1.29)*1.24 (1.12, 1.38)*
Anesthesia technique
 GeneralReference categoryReference categoryReference category
 Epidural0.97 (0.80, 1.12)1.11 (0.51, 2.36)1.13 (0.81, 1.57)
 Spinal0.63 (0.57, 0.69)*0.57 (0.41, 0.80)*1.08 (0.91, 1.29)
 Regional0.39 (0.33, 0.47)*0.66 (0.28, 1.57)*0.39 (0.29, 0.53)*
 Local0.32 (0.23, 0.43)*0.33 (0.15, 0.75)*0.36 (0.14, 0.91)*
 Monitored anesthesia care0.38 (0.34, 0.41)*0.34 (0.27, 0.44)*0.44 (0.35, 0.56)*
 Other0.28 (0.17, 0.46)*0.00 (0.00, α)0.56 (0.19, 1.66)
 None1.09 (0.50, 2.37)1.08 (0.12, 10.2)1.44 (0.19, 10.9)
Surgical specialty: vascular1.69 (1.62, 1.75)*
Male gender1.01 (0.98, 1.03)1.00 (.095, 1.09)0.90 (0.78, 0.94)*
Ventilator dependent3.24 (2.87, 3.65)*3.19 (2.47, 4.13)*4.22 (2.61, 6.81)*
COPD1.43 (1.37, 1.50)*1.60 (1.43, 1.78)*1.41 (1.23, 1.61)*
Cardiac risk factors1.27 (1.23, 1.31)*1.24 (1.12, 1.36)*1.33 (1.09, 1.63)*
On dialysis0.91 (0.84, 0.98)*1.13 (0.95, 1.33)1.02 (0.89, 1.17)
Steroid use1.48 (1.39, 1.59)*1.47 (1.25, 1.72)*1.07 (0.85, 1.36)
10% weight loss2.24 (2.07, 2.42)*2.22 (1.84, 2.67)*1.47 (1.04, 2.09)*
Sepsis
 NoneReference categoryReference categoryReference category
 Sepsis1.84 (1.72, 1.97)*1.89 (1.62, 2.19)*1.65 (1.34, 2.03)*
 Septic shock2.73 (2.40, 3.10)*3.42 (2.60, 4.49)*1.98 (1.21, 3.22)*
 SIRS1.63 (1.55, 1.71)*1.59 (1.40, 1.81)*1.70 (1.41, 2.04)*
Emergent case1.57 (1.51, 1.63)*1.50 (1.35, 1.66)*1.82 (1.54, 2.14)*
ASA class
 No ASA class assignedReference categoryReference categoryReference category
 No disturbance0.42 (0.29, 0.60)*0.60 (0.17, 2.083.39 (0.68, 16.9)
 Mild disturbance1.00 (0.70, 1.42)0.68 (0.25, 1.85)1.72 (0.54, 5.42)
 Severe disturbance2.29 (1.62, 3.26)*1.19 (0.44, 3.24)2.26 (0.73, 6.95)
 Life threatening4.92 (3.46, 7.00)*2.51 (0.92, 6.86)3.99 (1.29, 12.3)*
 Moribund5.85 (3.92, 8.73)*1.92 (0.64, 5.78)10.0 (2.37, 42.3)*
Wound classification
 CleanReference categoryReference categoryReference category
 Clean/contaminated1.99 (1.93, 2.07)*1.99 (1.82, 2.16)*1.32 (1.07, 1.63)*
 Contaminated1.98 (1.88, 2.08)*2.31 (2.02, 2.63)*1.31 (1.06, 1.62)*
 Dirty/infected2.38 (2.25, 2.51)*2.46 (2.15, 2.81)*1.15 (0.98, 1.35)

Values expressed as odds ratios (95% confidence intervals x, y). *Significance at . COPD: chronic obstructive pulmonary disease, ASA: American Society of Anesthesiologists, SIRS: systemic inflammatory response syndrome, and CI: confidence interval.