Table 1. Demographic characters of study before 1:1 PSM.
| Chest tube (days) | Drainage time ≤2 days (N=484) | SD/% | Drainage time >2 days (N=447) | SD/% | P |
|---|---|---|---|---|---|
| Age (year) | 0.710 | ||||
| Mean | 59.91 | 10.2 | 61.14 | 10.5 | |
| Gender | 0.001 | ||||
| Male | 240 | 49.6 | 278 | 62.2 | |
| Female | 244 | 50.4 | 169 | 37.8 | |
| FVC (L) | 0.554 | ||||
| Mean | 2.92 | 1.04 | 2.95 | 0.93 | |
| FEV1 (L) | 0.273 | ||||
| Mean | 2.23 | 0.81 | 2.18 | 0.74 | |
| CT-diameter (cm) | 0.006 | ||||
| Mean | 2.92 | 1.45 | 3.2 | 1.64 | |
| Smoking | 0.002 | ||||
| Yes | 134 | 27.7 | 167 | 37.4 | |
| No | 350 | 72.3 | 280 | 62.6 | |
| Family history | 0.864 | ||||
| Yes | 6 | 1.2 | 5 | 1.1 | |
| No | 478 | 98.8 | 442 | 98.9 | |
| Basic disease | 0.779 | ||||
| Yes | 155 | 32.0 | 147 | 32.9 | |
| No | 329 | 68.0 | 300 | 67.1 | |
| Comorbidity | 0.792 | ||||
| Yes | 21 | 4.3 | 21 | 4.7 | |
| No | 463 | 95.7 | 426 | 95.3 | |
| Surgical approach | 0.208 | ||||
| Lobectomy resection | 452 | 93.4 | 426 | 95.3 | |
| Wedge resection | 32 | 6.6 | 21 | 4.7 | |
| Blood | 0.262 | ||||
| A | 120 | 24.8 | 135 | 30.3 | |
| B | 139 | 28.7 | 113 | 25.3 | |
| O | 185 | 38.2 | 159 | 35.6 | |
| AB | 40 | 8.3 | 39 | 8.7 | |
| Mutation state | 0.003 | ||||
| Yes | 83 | 17.1 | 78 | 17.4 | |
| No | 26 | 5.4 | 51 | 11.4 | |
| Unknow | 375 | 77.5 | 318 | 71.1 | |
| Tumor position | 0.628 | ||||
| Right upper | 149 | 30.8 | 145 | 32.4 | |
| Right middle | 39 | 8.1 | 43 | 9.6 | |
| Right lower | 86 | 17.8 | 86 | 19.2 | |
| Left upper | 132 | 27.3 | 111 | 24.8 | |
| Left lower | 78 | 16.1 | 61 | 13.6 | |
| Pathology | 0.001 | ||||
| Squamous cell carcinoma | 36 | 7.4 | 63 | 14.1 | |
| Adenocarcinoma | 418 | 86.4 | 343 | 76.7 | |
| Others | 30 | 6.2 | 41 | 9.2 | |
| Pathological staging | 0.001 | ||||
| I | 347 | 71.7 | 272 | 60.9 | |
| II | 45 | 9.3 | 54 | 12.1 | |
| III | 84 | 17.4 | 98 | 21.9 | |
| IV | 8 | 1.7 | 23 | 5.1 |
PSM, propensity score matching; SD, standard deviation; FVC, forced vital capacity; FEV1, forced expiratory volume in 1 second; CT, computed tomography.