Table 1 Baseline demographics before and after propensity score matching.
Variable | Overall (n = 4135) | After propensity score matching (n = 2360) | ||||
|---|---|---|---|---|---|---|
Laparoscopic (n = 2139) | Open (n = 1996) | P value | Laparoscopic (n = 1180) | Open (n = 1180) | P value | |
Age (y, mean ± SD) | 74.5 ± 7.2 | 73.2 ± 6.8 | < 0.001 | 73.9 ± 7.0 | 73.6 ± 6.9 | 0.295 |
Sex (n, %) | ||||||
Male | 1278 (59.7) | 1078 (54.0) | <0.001 | 702 (59.5) | 690 (58.5) | 0.616 |
Female | 861 (40.3) | 918 (46.0) | 478 (40.5) | 490 (41.5) | ||
ASA-PS (n, %) | ||||||
1 | 768 (35.9) | 621 (33.1) | 0.001 | 385 (32.6) | 362 (30.7) | 0.347 |
2 | 912 (42.6) | 868 (43.5) | 521 (44.2) | 556 (47.1) | ||
3 | 459 (21.5) | 507 (25.4) | 274 (23.2) | 262 (22.2) | ||
BMI (kg/m2, mean ± SD) | 23.9 ± 10.3 | 23.1 ± 9.7 | 0.010 | 23.5 ± 7.4 | 23.4 ± 7.1 | 0.738 |
Tumor size (mm, mean ± SD) | 37.6 ± 12.4 | 38.4 ± 11.5 | 0.033 | 37.9 ± 9.1 | 38.2 ± 9.3 | 0.428 |
Tumor site (n, %) | ||||||
Lower segment | 367 (17.2) | 274 (13.7) | <0.001 | 202 (17.1) | 195 (16.5) | 0.723 |
Lower to middle segment | 149 (6.9) | 101 (5.1) | 89 (7.5) | 73 (6.2) | ||
Middle segment | 806 (37.7) | 735 (36.8) | 427 (36.2) | 438 (37.1) | ||
Middle to upper segment | 235 (11.0) | 241 (12.1) | 156 (13.2) | 164 (13.9) | ||
Upper segment | 582 (27.2) | 645 (32.3) | 306 (26.0) | 310 (26.3) | ||
Previous abdominal surgery (n, %) | 234 (10.9) | 193 (9.7) | 0.180 | 119 (10.1) | 113 (9.6) | 0.678 |
Tumor stage (n, %) | ||||||
T1aN0M0 | 1455 (68.0) | 1419 (71.1) | 0.032 | 824 (69.8) | 833 (70.6) | 0.685 |
T1bN0M0 | 684 (32.0) | 577 (28.9) | 356 (30.2) | 347 (29.4) | ||
Tumor grade (n, %) | ||||||
1 | 599 (28.0) | 486 (24.3) | 0.056 | 312 (26.5) | 298 (25.3) | 0.788 |
2 | 933 (43.6) | 928 (46.5) | 535 (45.3) | 554 (46.9) | ||
3 | 545 (25.5) | 527 (26.4) | 305 (25.8) | 296 (25.1) | ||
Unclassified | 62 (2.9) | 55 (2.8) | 28 (2.4) | 32 (2.7) | ||
Histopathological type (n, %) | ||||||
Papillary adenocarcinoma | 651 (30.4) | 496 (24.8) | <0.001 | 349 (29.6) | 317 (26.9) | 0.219 |
Tubular adenocarcinoma | 507 (23.7) | 568 (28.5) | 286 (24.2) | 326 (27.6) | ||
Poorly differentiated adenocarcinoma | 296 (13.8) | 281 (14.1) | 166 (14.1) | 174 (14.7) | ||
Mucinous adenocarcinoma | 359 (16.8) | 392 (19.6) | 212 (18.0) | 223 (18.9) | ||
Signet-ring cell carcinoma | 215 (10.1) | 163 (8.2) | 115 (9.7) | 95 (8.1) | ||
Others | 111 (5.2) | 96 (4.8) | 52 (4.4) | 45 (3.8) | ||
Lauren’s type (n, %) | ||||||
Intestinal | 1222 (57.1) | 1097 (55.0) | <0.001 | 670 (56.8) | 647 (54.8) | 0.149 |
Diffuse | 813 (38.0) | 734 (36.8) | 450 (38.1) | 451 (38.2) | ||
Mixed | 104 (4.9) | 165 (8.2) | 60 (5.1) | 82 (7.0) | ||
Local extent of gastric resection (n, %) | ||||||
Subtotal gastrectomy | 1960 (91.6) | 1800 (90.2) | 0.104 | 1072 (90.8) | 1063 (90.1) | 0.528 |
Total gastrectomy | 179 (8.4) | 196 (9.8) | 108 (9.2) | 117 (9.9) | ||
Surgical margins (n, %) | ||||||
Negative | 1887 (88.2) | 1716 (86.0) | 0.031 | 1027 (87.0) | 1016 (86.1) | 0.507 |
Positive | 252 (11.8) | 280 (14.0) | 153 (13.0) | 164 (13.9) | ||
Postoperative chemotherapy(n, %) | ||||||
Yes | 93 (4.3) | 96 (4.8) | 0.019 | 53 (4.5) | 56 (4.7) | 0.714 |
No | 1905 (89.1) | 1808 (90.6) | 1052 (89.2) | 1058 (89.7) | ||
Unknown | 141 (6.6) | 92 (4.6) | 75 (6.3) | 66 (5.6) | ||
Postoperative radiotherapy(n, %) | ||||||
Yes | 142 (6.6) | 157 (7.9) | 0.099 | 81 (6.9) | 86 (7.3) | 0.514 |
No | 1928 (90.2) | 1791 (89.7) | 1060 (89.8) | 1064 (90.2) | ||
Unknown | 69 (3.2) | 48 (2.4) | 39 (3.3) | 30 (2.5) | ||
