Table 1 Patient characteristics before and after propensity score matching
Characteristic | Unmatched comparison | Matched comparison | ||||
|---|---|---|---|---|---|---|
Non-elderly group (n = 373) | Elderly group (n = 59) | Standardized difference | Non-elderly group (n = 100) | Elderly group (n = 50) | Standardized difference | |
Sex (male/female) | 314 / 59 | 59 / 9 | 0.016 | 84 / 16 | 42 / 8 | 0.000 |
Neoadjuvant treatment | ||||||
Not performed | 149 (40%) | 34 (58%) | 0.359 | 53 (53%) | 29 (58%) | 0.101 |
Performed | 224 (60%) | 25 (42%) | 47 (47%) | 21 (42%) | ||
Surgical approach | ||||||
Open | 346 (93%) | 52 (88%) | 0.158 | 89 (89%) | 45 (90%) | 0.033 |
Thoracoscopic | 27 (7%) | 7 (12%) | 11 (11%) | 5 (10%) | ||
Number of field dissected | ||||||
2-field dissection | 221 (59%) | 49 (83%) | 0.528 | 78 (78%) | 40 (80%) | 0.049 |
3-field dissection | 152 (41%) | 10 (17%) | 22 (22%) | 10 (20%) | ||
Tumor size (mm), mean ± SD | 35.4 ± 21.6 | 45.2 ± 23.6 | − 0.432 | 38.3 ± 21.0 | 44.1 ± 21.6 | −0.212 |
T factor | ||||||
pT0/pTis | 25 (7%) | 2 (3%) | 0.351 | 1 (1%) | 0 | 0.159 |
pT1 | 157 (42%) | 29 (49%) | 51 (51%) | 27 (54%) | ||
pT2 | 54 (14%) | 7 (12%) | 11 (11%) | 6 (12%) | ||
pT3 | 129 (35%) | 21 (36%) | 37 (37%) | 17 (34%) | ||
pT4 | 8 (2%) | 0 | 0 | 0 | ||
N factor | ||||||
pN0 | 172 (46%) | 30 (51%) | 0.242 | 45 (45%) | 25 (50%) | 0.183 |
pN1 | 102 (27%) | 17 (29%) | 30 (30%) | 15 (30%) | ||
pN2 | 65 (18%) | 10 (17%) | 20 (20%) | 9 (18%) | ||
pN3 | 34 (9%) | 2 (3%) | 5 (5%) | 1 (2%) | ||
TNM stage | ||||||
0 | 17 (4%) | 2 (3%) | 0.556 | 1 (1%) | 0 | 0.3000 |
I | 97 (26%) | 23 (39%) | 36 (36%) | 21 (42%) | ||
II | 108 (29%) | 10 (17%) | 20 (20%) | 9 (18%) | ||
III | 103 (28%) | 22 (38%) | 36 (36%) | 19 (38%) | ||
IV | 48 (13%) | 2 (3%) | 7 (7%) | 1 (2%) | ||