Table 4.
Optimal discrimination limits for the percent and absolute change in serum creatinine associated with adverse postoperative outcomes for training and validation cohorts.
| Outcome | Percent change in sCr Model (ratio) | Absolute change in sCr Model (mg/dl) |
|---|---|---|
| Hospital mortality | ||
| Optimal Discrimination limit (Sensitivity, specificity) | 1.68 (0.80, 0.80) | 0.31 mg/dl (0.81, 0.75) |
| NSQIP-AKI cut-off1 (Sensitivity, specificity) | 2 mg/dl (0.28, 0.98) | |
| Training AUC2 (95% CI) | 0.87 (0.86, 0.88) | 0.86 (0.84, 0.87) |
| Validation AUC2 (95% CI) | 0.85 (0.82, 0.88) | 0.83 (0.80, 0.87) |
|
| ||
| 90-day mortality | ||
| Optimal Discrimination limit (Sensitivity, specificity) | 1.66 (0.61, 0.77) | 0.40 mg/dl (0.59, 0.77) |
| NSQIP-AKI cut-off1 (Sensitivity, specificity) | 2 mg/dl (0.18, 0.98) | |
| Training AUC2 (95% CI) | 0.75 (0.73, 0.76) | 0.73 (0.71, 0.74) |
| Validation AUC2 (95% CI) | 0.79 (0.76, 0.83) | 0.77 (0.73, 0.81) |
|
| ||
| Sepsis | ||
| Optimal Discrimination limit (Sensitivity, specificity) | 1.70 (0.85, 0.80) | 0.32 mg/dl (0.82, 0.76) |
| NSQIP-AKI cut-off (Sensitivity, specificity) | 2 mg/dl (0.24, 0.98) | |
| Training AUC (95% CI) | 0.89 (0.88, 0.90) | 0.86 (0.85, 0.87) |
| Validation AUC (95% CI) | 0.90 (0.88, 0.92) | 0.87 (0.84, 0.89) |
|
| ||
| Severe sepsis | ||
| Optimal Discrimination limit (Sensitivity, specificity) | 1.70 (0.90, 0.80) | 0.32 mg/dl (0.87, 0.75) |
| NSQIP-AKI cut-off (Sensitivity, specificity) | 2 mg/dl (0.27, 0.98) | |
| Training AUC (95% CI) | 0.92 (0.91, 0.93) | 0.89 (0.88, 0.90) |
| Validation AUC (95% CI) | 0.93 (0.91, 0.94) | 0.90 (0.88, 0.92) |
|
| ||
| Postoperative surgical infections | ||
| Optimal Discrimination limit (Sensitivity, specificity) | 1.38 (0.67, 0.54) | 0.28 mg/dl (0.56, 0.61) |
| NSQIP-AKI cut-off (Sensitivity, specificity) | 2.0 mg/dl (0.06, 0.97) | |
| Training AUC (95% CI) | 0.64 (0.62, 0.65) | 0.61 (0.60, 0.63) |
| Validation AUC (95% CI) | 0.66 (0.63, 0.89) | 0.63 (0.60, 0.66) |
|
| ||
| Mechanical wound complications | ||
| Optimal Discrimination limit (Sensitivity, specificity) | 1.50 (0.58, 0.65) | 0.23 mg/dl (0.60, 0.60) |
| NSQIP-AKI cut-off (Sensitivity, specificity) | 2.0 mg/dl (0.07, 0.97) | |
| Training AUC (95% CI) | 0.65 (0.64, 0.67) | 0.63 (0.62, 0.65) |
| Validation AUC (95% CI) | 0.65 (0.62, 0.68) | 0.63 (0.60, 0.66) |
|
| ||
| Procedural complications | ||
| Optimal Discrimination limit (Sensitivity, specificity) | 1.48 (0.59, 0.65) | 0.23 mg/dl (0.61, 0.61) |
| NSQIP-AKI cut-off (Sensitivity, specificity) | 2.0 mg/dl (0.07, 0.98) | |
| Training AUC (95% CI) | 0.66 (0.64,0.67) | 0.65 (0.63, 0.66) |
| Validation AUC (95% CI) | 0.68 (0.65, 0.71) | 0.67 (0.64, 0.70) |
|
| ||
| Mechanical ventilation | ||
| Optimal Discrimination limit (Sensitivity, specificity) | 1.43 (0.71, 0.69) | 0.23 mg/dl (0.70, 0.68) |
| NSQIP-AKI cut-off (Sensitivity, specificity) | 2 mg/dl (0.14, 0.98) | |
| Training AUC (95% CI) | 0.76 (0.76, 0.77) | 0.75 (0.75, 0.76) |
| Validation AUC (95% CI) | 0.78 (0.77, 0.80)** | 0.77 (0.76, 0.78)** |
|
| ||
| Long term mechanical ventilation6 | ||
| Optimal Discrimination limit (Sensitivity, specificity) | 1.65 (0.70, 0.78) | 0.31 mg/dl (0.64, 0.76) |
| NSQIP-AKI cut-off (Sensitivity, specificity) | 2 mg/dl (0.16, 0.98) | |
| Training AUC (95% CI) | 0.80 (0.79, 0.81) | 0.75 (0.74, 0.77) |
| Validation AUC (95% CI) | 0.84 (0.82, 0.86)** | 0.79 (0.76, 0.81)** |
|
| ||
| Pulmonary complications | ||
| Optimal Discrimination limit (Sensitivity, specificity) | 1.45 (0.70, 0.65) | 0.23 mg/dl (0.71, 0.61) |
| NSQIP-AKI cut-off (Sensitivity, specificity) | 2 mg/dl (0.1, 0.98) | |
| Training AUC (95% CI) | 0.73 (0.72, 0.74) | 0.71 (0.70, 0.72) |
| Validation AUC (95% CI) | 0.73 (0.70, 0.75) | 0.71 (0.69, 0.73) |
|
| ||
| Cardiovascular complications | ||
| Optimal Discrimination limit (Sensitivity, specificity) | 1.41 (0.67, 0.60) | 0.23 mg/dl (0.68, 0.60) |
| NSQIP-AKI cut-off (Sensitivity, specificity) | 2 mg/dl (0.10, 0.97) | |
| Training AUC (95% CI) | 0.68 (0.66,0.69) | 0.68 (0.66, 0.69) |
| Validation AUC (95% CI) | 0.66 (0.63, 0.69) | 0.65 (0.62, 0.68) |
|
| ||
| Neurological complications | ||
| Optimal Discrimination limit (Sensitivity, specificity) | 1.61 (0.45, 0.75) | 0.21 mg/dl (0.56, 0.58) |
| NSQIP-AKI cut-off (Sensitivity, specificity) | 2 mg/dl (0.05, 0.97) | |
| Training AUC (95% CI) | 0.62 (0.60, 0.64) | 0.59 (0.57, 0.61) |
| Validation AUC (95% CI) | 0.64 (0.60, 0.69) | 0.60 (0.55, 0.64) |
|
| ||
| GI complications | ||
| Optimal Discrimination limit (Sensitivity, specificity) | 1.46 (0.57, 0.63) | 0.26 mg/dl (0.58, 0.60) |
| NSQIP-AKI cut-off (Sensitivity, specificity) | 2 mg/dl (0.05, 0.97) | |
| Training AUC (95% CI) | 0.63 (0.61, 0.65) | 0.62 (0.60, 0.63) |
| Validation AUC (95% CI) | 0.65 (0.61, 0.69) | 0.64 (0.59, 0.68) |
1
NSQIP sensitivity and specificity were found along the ROC curve for absolute change in sCr model applying the NSQIP-AKI cut-off of 2.0 mg/dl change from RsCr.
2
Training AUC (95% CI) and validation AUC (95% CI) indicate area under receiver operator curve with 95% confidence intervals for each univariable model applied in training and validation cohort, respectively.
**
p-value < 0.05 for difference in AUC (95% CI) between the models fit to training cohort and validation cohort.