Table 1.
Patient characteristics in derivation and validation cohort
| Demographics | Full Cohort N=9749 |
Derivation Cohort N=6825 |
Validation Cohort N=2924 |
P-value |
|---|---|---|---|---|
| Age, years (SD) | 67.6 (7.9) | 67.6 (8.0) | 67.6 (7.8) | 0.908 |
| Sex (%) | 0.223 | |||
| Male | 9,391 (96.3) | 6,564 (96.2) | 2,827 (96.7) | |
| Female | 358 (3.7) | 261 (3.8) | 97 (3.3) | |
| Race (%)a | 0.399 | |||
| White | 8,067 (82.8) | 5,636 (82.8) | 2,431 (83.1) | |
| Black | 1,457 (15.0) | 1,028 (15.1) | 429 (14.7) | |
| Other | 131 (1.3) | 99 (1.5) | 32 (1.1) | |
| Unknown | 94 (1.0) | 62 (0.9) | 32 (1.1) | |
| Smoking status (%)b | 0.906 | |||
| Current | 5,701 (58.5) | 4,001 (58.6) | 1,700 (58.1) | |
| Former | 3,915 (40.2) | 2,731 (40.0) | 1,184 (40.5) | |
| Never | 133 (1.4) | 93 (1.4) | 40 (1.4) | |
| BMI, kg/m2 (SD)c | 27.3 (5.3) | 27.2 (5.4) | 27.2 (5.3) | 0.994 |
| BMI category (%) | 0.784 | |||
| <18.5 | 292 (3.2) | 206 (3.2) | 86 (3.1) | |
| 18.5-24.9 | 3,125 (33.8) | 2,199 (34.1) | 926 (33.3) | |
| 25.0-29.9 | 3,328 (36.0) | 2,310 (35.8) | 1,018 (36.6) | |
| 30.0-34.9 | 1,777 (19.2) | 1,228 (19.0) | 549 (19.7) | |
| ≥35.0 | 712 (7.7) | 506 (7.9) | 206 (7.4) | |
| FEV1% (IQR)c | 78 (66-95) | 78 (65-95) | 79 (66-96) | 0.204 |
| Charlson/Deyo score (IQR) | 6.9 (2.2) | 6.9 (2.2) | 6.9 (2.2) | 0.542 |
| Functional Status (%)d,c | 0.622 | |||
| Independent | 7,449 (96.9) | 5,210 (96.8) | 2,239 (97.0) | |
| Partially or Fully Dependent | 238 (3.1) | 170 (3.2) | 68 (3.0) | |
| Treatment Characteristics | ||||
| Wait time to surgery, days | ||||
| Median (IQR) | 63 (41-96) | 62 (41-95) | 63 (41-97) | 0.161 |
| >12 weeks (%) | 3,046 (31.2) | 2,105 (30.8) | 941 (32.2) | 0.191 |
| Tumor size, mm (%) | 0.554 | |||
| ≤10 | 861 (8.8) | 591 (8.7) | 270 (9.2) | |
| 11-20mm | 3,831 (39.3) | 2,656 (38.9) | 1,175 (40.2) | |
| 21-30mm | 2,653 (27.2) | 1,871 (27.4) | 782 (26.7) | |
| 31-40mm | 1,746 (15.1) | 1,041 (15.3) | 435 (14.9) | |
| 40+ mm | 719 (7.4) | 520 (7.6) | 199 (6.8) | |
| Unknown | 209 (2.1) | 146 (2.1) | 63 (2.2) | |
| Resection (%) | 0.876 | |||
| Lobectomy | 6,913 (70.9) | 4,850 (71.1) | 2,059 (70.4) | |
| Wedge | 2,139 (22.0) | 1,489 (21.8) | 650 (22.3) | |
| Segment | 541 (5.6) | 376 (5.5) | 165 (5.7) | |
| Pneumonectomy | 156 (1.6) | 106 (1.6) | 50 (1.7) | |
| Surgical approach (%)c | 0.436 | |||
| VATS | 4,032 (41.5) | 2,840 (41.7) | 1,192 (40.9) | |
| Thoracotomy | 5,690 (58.5) | 3,966 (58.3) | 1,724 (59.1) | |
| Histology (%) | 0.627 | |||
| Adenocarcinoma | 5,195 (53.3) | 3,618 (53.0) | 1,577 (53.9) | |
| Squamous cell | 3,294 (33.8) | 2,313 (33.9) | 981 (33.6) | |
| Other | 1,260 (12.9) | 894 (13.1) | 366 (12.5) |
BMI=body mass index; FEV=forced expiratory volume; VATS=video-assisted thoracoscopic surgery
a
Defined according to American College of Surgery Facility Oncology Registry Data Standards manual.
b
Smoking status (current, former, or never) was assessed at the time of surgery.
c
Missing data were present for BMI (n=515, 5.3%), FEV1 (2333, 23.9%), functional status (2062, 21.2%) and surgical approach (n=27, 0.3%).
d
Defined according to VASQIP as independent, partially dependent (patient requires assistance for some activities of daily living) and totally dependent (patient requires assistance for all activities of daily living)