Characteristics of operable patients with early-stage NSCLC, before and after applying propensity score overlap weighting
| Crude | Weighted* | |||||
| Variable | FEV1 <82%pred (n=234) | FEV1 ≥82%pred (n=541) | Standardised mean difference | FEV1 <82%pred | FEV1 ≥82%pred | Standardised mean difference |
| Male, n (%) | 172 (73.5) | 288 (53.2) | 0.43 | 67.1 | 67.1 | <0.001 |
| Age, mean±SD, (years) | 59±9 | 58±9 | 0.14 | 58±9 | 58±9 | <0.001 |
| BMI, kg/m2, mean±SD | 23.7±3.1 | 23.6±2.8 | 0.04 | 23.7±3.1 | 23.7±2.9 | <0.001 |
| Ever smoked, n (%) | 126 (53.8) | 192 (35.5) | 0.38 | 47.8 | 47.8 | <0.001 |
| MET, mean±SD | 6.3±1.3 | 6.6±1.3 | 0.23 | 6.5±1.4 | 6.5±1.3 | |
| Medical history, n (%) | ||||||
| Hypertension | 51 (21.8) | 114 (21.1) | 0.02 | 22.2 | 22.2 | <0.001 |
| Dyslipidaemia | 30 (12.8) | 45 (8.3) | 0.15 | 11.3 | 11.3 | <0.001 |
| T2DM | 23 (9.8) | 44 (8.1) | 0.06 | 10.0 | 10.0 | <0.001 |
| CAD | 43 (18.4) | 106 (19.6) | 0.03 | 19.0 | 19.0 | <0.001 |
| Cerebrovascular disease | 5 (2.1) | 12 (2.2) | 0.01 | 1.6 | 1.6 | <0.001 |
| Chronic bronchitis | 13 (5.6) | 29 (5.4) | 0.01 | 5.5 | 5.5 | <0.001 |
| Histology, n (%) | 0.45 | <0.001 | ||||
| Adenomatous | 140 (59.8) | 431 (79.7) | 67.9 | 67.9 | ||
| Squamous | 80 (34.2) | 86 (15.9) | 26.5 | 26.5 | ||
| Others | 14 (6.0) | 24 (4.4) | 5.7 | 5.7 | ||
| Type of lung resections, n (%) | 0.26 | <0.001 | ||||
| Pneumonectomy | 14 (6.0) | 11 (2.0) | 4.0 | 4.0 | ||
| Lobectomy | 210 (89.7) | 498 (92.1) | 91.6 | 91.6 | ||
| Segmentectomy | 5 (2.1) | 10 (1.8) | 2.1 | 2.1 | ||
| Wedge resection | 1 (0.4) | 4 (0.7) | 0.5 | 0.5 | ||
| No resection† | 2 (0.9) | 2 (0.4) | 0.7 | 0.7 | ||
| Two lung lobes | 2 (0.9) | 16 (3.0) | 1.1 | 1.1 | ||
| Clinical stage, n (%) | 0.21 | <0.001 | ||||
| 0 | 6 (2.6) | 13 (2.4) | 2.6 | 2.6 | ||
| I | 136 (58.1) | 364 (67.3) | 62.5 | 62.5 | ||
| II | 34 (14.5) | 71 (13.1) | 13.6 | 13.6 | ||
| IIIA | 58 (24.8) | 93 (17.2) | 21.3 | 21.3 | ||
*After applying overlap weighting, individual data points no longer corresponds to a single entity. Consequently, raw counts for categorical variables are not reported; instead, the percentages are presented.
†Explorative thoracotomy without lung resection.
BMI, body mass index; CAD, coronary artery disease; FEV1, forced expiratory volume in 1 s; MET, metabolic equivalent; NSCLC, non-small cell lung cancer; T2DM, type 2 diabetes mellitus.