Table 1 Baseline characteristics before and after PSM
Characteristics | Before PSM | After PSM | ||||
|---|---|---|---|---|---|---|
Younger (1335) | Older (1039) | p-value | Younger (784) | Older (784) | p-value | |
Age (year) | 52 (46.58) | 69 (66.74) | < 0.001* | 53 (46.59) | 69 (65.74) | < 0.001* |
Sex | 0.191 | 0.757 | ||||
Male | 756 (56.6) | 617 (59.4) | 472 (60.2) | 465 (59.3) | ||
Female | 579 (43.4) | 422 (40.6) | 312 (39.8) | 319 (40.7) | ||
BMI (kg/m2) | 23.1 (20.4, 25.0) | 22.7 (20.4, 24.6) | 0.710 | 22.6 (20.3,25.0) | 22.6 (20.2, 24.8) | 0.960 |
Diabetes mellitus | 177 (13.3) | 263 (25.3) | < 0.001* | 135 (17.2) | 144 (18.4) | 0.597 |
Hypertension | 253 (19.0) | 488 (47.0) | < 0.001* | 243 (31.0) | 240 (30.6) | 0.913 |
Tumor location | 0.028* | 0.950 | ||||
Colon | 1082 (81.0) | 803 (77.3) | 625 (79.7) | 623 (79.5) | ||
Rectum | 253 (19.0) | 236 (22.7) | 159 (20.3) | 161 (20.5) | ||
Tumor differentiation | 0.047* | 0.975 | ||||
Low | 392 (29.4) | 259 (24.9) | 205 (26.1) | 207 (26.4) | ||
Medium | 924 (69.2) | 761 (73.2) | 566 (72.2) | 565 (72.1) | ||
High | 19 (1.4) | 19 (1.8) | 13 (1.7) | 12 (1.5) | ||
Tumor pathological stage | 0.359 | 0.728 | ||||
0 | 9 (0.7) | 6 (0.6) | 7 (0.9) | 4 (0.5) | ||
I | 156 (11.7) | 120 (11.5) | 84 (10.7) | 87 (11.1) | ||
II | 361 (27.0) | 286 (27.5) | 213 (27.2) | 226 (28.8) | ||
III | 408 (30.6) | 282 (27.1) | 228 (29.1) | 210 (26.8) | ||
IV | 401 (30.0) | 345 (33.2) | 252 (32.1) | 257 (32.8) | ||
Surgical characteristic | 0.075 | 0.430 | ||||
R2 | 182 (13.6) | 126 (12.1) | 95 (12.1) | 108 (13.8) | ||
R1 | 57 (4.3) | 29 (2.8) | 25 (3.2) | 19 (2.4) | ||
R0 | 1096 (82.1) | 884 (85.1) | 664 (84.7) | 657 (83.8) | ||
Adjuvant chemotherapy | 419 (31.4) | 224 (21.6) | < 0.001* | 191 (24.4) | 183 (23.3) | 0.678 |
Adjuvant radiotherapy | 37 (2.8) | 12 (1.2) | 0.009* | 8 (1.0) | 10 (1.3) | 0.813 |