Table 1.
Clinical Characteristics of Patients in Discovery and Replication Sets
| Variable | Discovery N = 264 |
Replication N = 264 |
Total N = 528 |
|---|---|---|---|
| Mean age (y) | 65 | 66 | 66 |
| Sex | |||
| Male | 141 (53%) | 139 (53%) | 280 (53%) |
| Female | 123 (47%) | 125 (47%) | 248 (47%) |
| Smoking Status | |||
| Never smoker | 54 (21%) | 47 (18%) | 101 (19%) |
| Former smoker | 142 (54%) | 151 (57%) | 293 (55%) |
| Current/recent smoker | 65 (25%) | 64 (24%) | 129 (24%) |
| Pack years (mean) | 53 | 49 | 51 |
| FEV1 ≤ 50% predicted | 137 (53%) | 127 (49%) | 264 (51%) |
| DLCO ≤ 50% predicted | 118 (49%) | 127 (51%) | 245 (50%) |
| Preoperative chemotherapy | 37 (14%) | 39 (15%) | 76 (14%) |
| Thoracoscopic approach | 45 (17%) | 45 (17%) | 90 (17%) |
| Chest wall resection | 12 (5%) | 17 (6%) | 29 (6%) |
| Intraoperative transfusion | 12 (5%) | 11 (4%) | 23 (4%) |
| Pathologic tumor stage | |||
| T1 | 114 (43%) | 115 (44%) | 229 (43%) |
| T2 | 124 (47%) | 121 (46%) | 245 (46%) |
| T3 | 14 (5%) | 11 (4%) | 25 (43%) |
| T4 | 8 (3%) | 13 (5%) | 21 (4%) |
| Any pulmonary complication | 79 (31%) | 85 (33%) | 164 (31%) |
| Prolonged air leak | 39 (15%) | 43 (16%) | 82 (16%) |
| Discharge on home oxygen | 32 (12%) | 29 (11%) | 61 (12%) |
| Pneumonia | 24 (9%) | 26 (10%) | 50 (10%) |
| Atelectasis requiring bronchoscopy | 10 (4%) | 7 (3%) | 17 (4%) |
There were no significant differences between the groups with respect to epidural use, preoperative radiation, tumor location, body mass index, diabetes, or other comorbidities (p > 0.05). The following pulmonary complications each occurred in less than 1.5% of patients: aspiration, acute respiratory distress syndrome, bronchopleural fistula, pulmonary embolus, and initial ventilatory support longer than 48 hours.
DLCO = diffusing capacity of lung for carbon monoxide; FEV1 = forced expiratory volume in the first second of expiration.