Exhibit 53. Results of logistic regression using the 60% derivation set, including each of the five surgical procedures as a possible risk factor
| Variable | Estimate | tValue | Probability |
|---|---|---|---|
| Intercept | -5.47 | -4.82 | 0.0000 |
| Emergency surgery | 0.74 | 3.05 | 0.0023 |
| Chronic kidney disease | -1.84 | -2.49 | 0.0130 |
| Male | 0.0130 | 2.37 | 0.0180 |
| History of MRSA | 1.50 | 4.74 | 0.0000 |
| No. of surgeons* | 0.79 | 2.39 | 0.0168 |
| Postop admission | 2.58 | 9.73 | 0.0000 |
| Preop glucose* | 0.00 | 0.55 | 0.5893 |
| Preop hemoglobin | -0.24 | -4.04 | 0.0001 |
| Preop stay | 0.02 | 0.82 | 0.4096 |
| Surgery duration | 0.00 | 1.61 | 0.1073 |
| Herniorrhaphy | 0.88 | 2.90 | 0.0037 |
* Additional Intermountain risk factor.
Exhibit 54. Results of logistic regression using the 40% validation set, and including each of the five surgical procedures as a possible risk factor
| Variable | Estimate | tValue | Probability |
|---|---|---|---|
| Intercept | -4.97 | -3.66 | 0.0003 |
| Emergency surgery | 0.01 | 0.04 | 0.9686 |
| Chronic kidney disease | -1.54 | -2.05 | 0.0400 |
| Male | 0.13 | 0.60 | 0.5510 |
| History of MRSA | 1.12 | 3.10 | 0.0020 |
| No. of surgeons* | 0.83 | 1.82 | 0.0695 |
| Postop admission | 1.95 | 8.07 | 0.0000 |
| Preop glucose* | 0.00 | -1.00 | 0.3223 |
| Preop hemoglobin | -0.17 | -2.62 | 0.0090 |
| Preop stay | 0.04 | 1.13 | 0.2574 |
| Surgery duration | 0.00 | 3.07 | 0.0021 |
| Herniorrhaphy | 0.84 | 2.76 | 0.0059 |
* Additional Intermountain risk factor.
Exhibit 55. Results of logistic regression using the combined derivation and validation sets and including each of the five surgical procedures as a possible risk factor
| Variable | Estimate | tValue | Probability |
|---|---|---|---|
| Intercept | -5.41 | -6.37 | 0.0000 |
| Elective surgery | 0.42 | 0.42 | 0.0246 |
| Chronic kidney disease | -1.68 | -3.20 | 0.0014 |
| Male | 0.31 | 1.99 | 0.0469 |
| History of MRSA | 1.35 | 5.70 | 0.0000 |
| No. of surgeons* | 0.80 | 3.05 | 0.0023 |
| Postop admission | 0.0023 | 12.74 | 0.0000 |
| Preop glucose* | 0.00 | -0.27 | 0.7842 |
| Preop hemoglobin | -0.19 | -4.23 | 0.0000 |
| Preop stay | 0.04 | 1.51 | 0.1308 |
| Surgery duration | 0.00 | 3.42 | 0.0006 |
| Herniorrhaphy | 0.86 | 4.02 | 0.0001 |
* Additional Intermountain risk factor.
