Table 1.
Patient characteristics.
| Variable | Derivation cohort n = 480 (%) | Validation cohort n = 240 (%) | p value |
|---|---|---|---|
| Age, years (mean ± SD) | 23–86 (66 ± 10) | 38–87 (67 ± 10) | 0.245 |
| Sex, male | 236 (49) | 122 (51) | 0.673 |
| Any smoking history | 271 (57) | 146 (61) | 0.262 |
| Comorbidities, present | 227 (47) | 132 (55) | 0.051 |
| FEV1.0, L (mean ± SD) | 0.98–4.93 (2.36 ± 0.67) | 0.89–4.93 (2.28 ± 0.64) | 0.125 |
| FEV1.0% (mean ± SD) | 39–96 (73 ± 9) | 35–93 (73 ± 10) | 0.795 |
| Clinical stage |
(0-IA2 vs. IA3) 0.163 |
||
| 0 | 32 (7) | 13 (6) | |
| IA1 | 94 (20) | 43 (18) | |
| IA2 | 201 (42) | 95 (40) | |
| IA3 | 153 (32) | 89 (37) | |
| Pathological stage |
(I vs. II-III) 0.234 |
||
| IA | 312 (65) | 164 (68) | |
| IB | 92 (19) | 46 (19) | |
| II | 40 (8) | 16 (7) | |
| III | 36 (8) | 14 (6) | |
| Histology | 0.274 | ||
| Adenocarcinoma | 422 (88) | 204 (85) | |
| Others | 58 (12) | 36 (15) | |
| Pathological lymph-node status |
(N0 vs. N1-3) 0.869 |
||
| N0 | 420 (88) | 213 (89) | |
| N1 | 25 (5) | 13 (5) | |
| N2 | 31 (7) | 14 (6) | |
| N3 | 4 (1) | 0 | |
| Surgical procedure | 0.008 | ||
| Lobectomy | 430 (90) | 229 (95) | |
| Segmentectomy | 50 (10) | 11 (5) | |
SD standard deviation; FEVforced expiratory volume.