Table 1. Clinical characteristics of the included patients before and after propensity-score matching.
| Characteristics | Before PSM | After PSM | |||||
|---|---|---|---|---|---|---|---|
| Uniport (n=400) | Three-port (n=2,230) | P value | Uniport (n=400) | Three-port (n=1,200) | P value | ||
| Age at surgery (years) | <0.001 | 0.63 | |||||
| Mean (SD) | 52.40 (11.50) | 54.71 (11.33) | 52.40 (11.50) | 52.71 (11.42) | |||
| Median [IQR] | 52.00 [45.00, 60.00] | 54.00 [47.00, 63.00] | 52.00 [45.00, 60.00] | 53.00 [45.00, 60.25] | |||
| Sex | 0.12 | 0.65 | |||||
| Female | 290 (72.50) | 1527 (68.48) | 290 (72.50) | 854 (71.17) | |||
| Male | 110 (27.50) | 703 (31.52) | 110 (27.50) | 346 (28.83) | |||
| FEV1% | 0.43 | 0.85 | |||||
| Mean (SD) | 107.33 (14.87) | 106.58 (16.65) | 107.33 (14.87) | 107.51 (15.98) | |||
| Median [IQR] | 106.55 [98.10, 116.70] | 106.40 [97.10, 116.40] | 106.55 [98.10, 116.70] | 106.90 [97.80, 116.85] | |||
| DLCO% | 0.49 | 0.90 | |||||
| Mean (SD) | 101.79 (14.83) | 101.16 (15.86) | 101.79 (14.83) | 101.91 (15.39) | |||
| Median [IQR] | 99.60 [92.40, 111.70] | 100.20 [90.10, 110.60] | 99.60 [92.40, 111.70] | 100.55 [91.20, 110.60] | 0.85 | ||
| Tumor size (cm) | 0.014 | 0.95 | |||||
| Mean (SD) | 1.13 (0.49) | 1.20 (0.56) | 1.13 (0.49) | 1.13 (0.50) | |||
| Median [IQR] | 1.00 [0.80, 1.40] | 1.00 [0.80, 1.50] | 1.00 [0.80, 1.40] | 1.00 [0.80, 1.40] | |||
| Clinical stage | 0.47 | >0.99 | |||||
| IA | 398 (99.50) | 2,207 (98.97) | 398 (99.50) | 1,192 (99.33) | |||
| IB | 2 (0.50) | 23 (1.03) | 2 (0.50) | 8 (0.67) | |||
| Development of pulmonary fissure | <0.001 | >0.99 | |||||
| Well | 246 (61.81) | 914 (41.58) | 246 (61.81) | 731 (61.90) | |||
| Incomplete | 152 (38.19) | 1,284 (58.42) | 152 (38.19) | 450 (38.10) | |||
| Missing | 2 (0.50) | 32 (1.43) | 2 (0.50) | 19 (1.50) | |||
| Pleural adhesions | 0.28 | 0.28 | |||||
| No | 133 (33.42) | 675 (30.54) | 133 (33.42) | 362 (30.34) | |||
| Yes | 265 (66.58) | 1,535 (69.46) | 265 (66.58) | 831 (69.66) | |||
| Missing | 2 (0.50) | 20 (0.89) | 2 (0.50) | 7 (0.58) | |||
| Histology | 0.14 | 0.39 | |||||
| AAH | 1 (0.28) | 27 (1.39) | 1 (0.28) | 18 (1.72) | |||
| AIS | 15 (4.27) | 87 (4.47) | 15 (4.27) | 34 (3.24) | |||
| MIA | 174 (49.57) | 836 (42.94) | 174 (49.57) | 535 (51.00) | |||
| Invasive adenocarcinoma | 148 (42.17) | 894 (45.92) | 148 (42.17) | 429 (40.90) | |||
| Squamous | 0 (0.00) | 10 (0.51) | 0 (0) | 0 (0) | |||
| Others* | 2 (0.57) | 10 (0.51) | 2 (0.57) | 5 (0.48) | |||
| Missing | 11 (3.13) | 83 (4.26) | 11 (3.13) | 28 (2.67) | |||
| Type of segments resected | 0.13 | 0.68 | |||||
| Simple | 123 (30.75) | 648 (29.06) | 96 (24.00) | 264 (22.00) | |||
| Complex | 181 (45.25) | 1,124 (50.40) | 181 (45.25) | 566 (47.17) | |||
| Combined | 96 (24.00) | 458 (20.54) | 123 (30.75) | 370 (30.83) | |||
| With segmentectomy | 9 (2.25) | 113 (5.06) | 9 (2.25) | 58 (4.83) | |||
| With wedge resection | 87 (21.75) | 345 (15.47) | 87 (21.75) | 206 (17.17) | |||
| Surgeon volume | <0.001 | 0.86 | |||||
| Low | 263 (65.75) | 1,221 (54.75) | 263 (65.75) | 781 (65.08) | |||
| High | 137 (34.25) | 1,009 (45.25) | 137 (34.25) | 419 (34.92) | |||
| Year of surgery | <0.001 | 0.83 | |||||
| 2014–2017 | 48 (12.00) | 649 (29.10) | 48 (12.00) | 151 (12.58) | |||
| 2018–2021 | 352 (88.00) | 1,581 (70.90) | 352 (88.00) | 1,049 (87.42) | |||
Data were presented as mean (SD), median [IQR] or number (percentage). *, others including large cell carcinoma, undifferentiated cancers, neuroendocrine tumor, salivary gland tumor and adenosquamous carcinoma. PSM, propensity-score matching; IQR, interquartile range; FEV1%, predicted forced expiratory volume in 1 second; DLCO%, predicted carbon monoxide diffusing capacity; AAH, atypical adenomatous hyperplasia; AIS, adenocarcinoma in situ; MIA, minimally invasive adenocarcinoma.