Table 4.
Characteristics of the training and validation datasets
| Parameter | Training (N = 1484) | Validation (N = 628) | P value |
|---|---|---|---|
| Age at surgery, y, mean (SD) | 59.1 (15.1) | 59.0 (15.9) | .9682 |
| Male sex, n (%) | 757 (51.0) | 312 (49.7) | .5765 |
| Postoperative patient-controlled analgesia, n (%) | 255 (17.3) | 78 (12.4) | .0054 |
| Chronic obstructive pulmonary disease, n (%) | 373 (25.2) | 112 (21.4) | .0809 |
| Last preoperative creatinine, mg/dL, mean (SD) | 1.0 (0.5) | 1.0 (0.9) | .5056 |
| Procedure group, n (%) | |||
| Chest wall/neck | 50 (3.4) | 24 (3.8) | .6053 |
| Lobectomy/segmentectomy | 476 (32.1) | 192 (30.6) | .4974 |
| Mediastinum/diaphragm | 187 (12.6) | 68 (10.8) | .2530 |
| Wedge resection | 401 (27.0) | 163 (26.0) | .6127 |
| Esophageal | 76 (5.1) | 81 (12.9) | <.0001 |
| Other procedures∗ | 94 (6.3) | 29 (4.6) | .1237 |
SD, Standard deviation.
∗
Other procedures include decortication, pleura, or others not indicated in the procedure groups listed above.