Table 2.
The difference between low and high ISS before and after IPTW.
| Characteristic | Before IPTW | P-value | After IPTW | P-value | ||
|---|---|---|---|---|---|---|
| Low ISS | High ISS | Low ISS | High ISS | |||
| n=249 | n=148 | n=392 | n=404 | |||
| Sex | 0.076 | 0.957 | ||||
| Female | 70 (28.1%) | 29 (19.6%) | 98.7 (25.2%) | 100.8 (24.9%) | ||
| Male | 179 (71.9%) | 119 (80.4%) | 292.9 (74.8%) | 303.5 (75.1%) | ||
| Age | 0.899 | 0.918 | ||||
| ≤65 | 204 (81.9%) | 122 (82.4%) | 322.2 (82.3%) | 334.3 (82.7%) | ||
| >65 | 45 (18.1%) | 26 (17.6%) | 69.5 (17.7%) | 69.9 (17.3%) | ||
| BMI (kg/m2) | 0.117 | 0.976 | ||||
| ≤18.5 | 29 (11.6%) | 14 (9.5%) | 41.4 (10.6%) | 44.1 (10.9%) | ||
| 18.5-25 | 183 (73.5%) | 100 (67.6%) | 282.4 (72.1%) | 293.6 (72.6%) | ||
| ≥25 | 37 (14.9%) | 34 (23.0%) | 67.8 (17.3%) | 66.6 (16.5%) | ||
| Histologic grade | 0.214 | 0.984 | ||||
| Gx/G1 | 96 (38.6%) | 68 (45.9%) | 160.0 (40.8%) | 163.0 (40.3%) | ||
| G2 | 137 (55.0%) | 68 (45.9%) | 204.3 (52.2%) | 211.1 (52.2%) | ||
| G3 | 16 (6.4%) | 12 (8.1%) | 27.4 (7.0%) | 30.2 (7.5%) | ||
| Tumor location | 0.018 | 0.912 | ||||
| Proximal | 23 (9.2%) | 8(5.4%) | 30.7 (7.8%) | 36.4 (9.0%) | ||
| Mid | 168 (67.5%) | 87 (58.8%) | 256.5 (65.5%) | 256.9 (63.5%) | ||
| Distal | 58 (23.3%) | 53 (35.8%) | 104.5 (26.7%) | 111.0 (27.5%) | ||
| T stage | 0.279 | 0.948 | ||||
| T1 | 69 (27.7%) | 29 (19.6%) | 97.9 (25.0%) | 96.0 (23.7%) | ||
| T2 | 43 (17.3%) | 31 (20.9%) | 73.0 (18.6%) | 84.9 (21.0%) | ||
| T3 | 130 (52.2%) | 85 (57.4%) | 211.1 (53.9%) | 215.4 (53.3%) | ||
| T4a | 7(2.8%) | 3(2.0%) | ||||
| N stage | 0.001 | 0.999 | ||||
| N0 | 131 (52.6%) | 59 (39.9%) | 189.8 (48.5%) | 195.0 (48.2%) | ||
| N1 | 72 (28.9%) | 37 (25.0%) | 110.0 (28.1%) | 114.7 (28.4%) | ||
| N2 | 40 (16.1%) | 40 (27.0%) | 75.6 (19.3%) | 76.8 (19.0%) | ||
| N3 | 6(2.4%) | 12 (8.1%) | 16.3 (4.2%) | 17.8 (4.4%) | ||
| TNM stage | 0.078 | 1.000 | ||||
| I | 62 (24.9%) | 32 (21.6%) | 94.0 (24.0%) | 96.3 (23.8%) | ||
| II | 82 (32.9%) | 36 (24.3%) | 117.0 (29.9%) | 119.3 (29.5%) | ||
| III | 98 (39.4%) | 71 (48.0%) | 163.2 (41.7%) | 169.9 (42.0%) | ||
| IVA | 7(2.8%) | 9(6.1%) | 17.6 (4.5%) | 18.8 (4.7%) | ||
| Lymphadenectomy | 0.065 | 0.998 | ||||
| Two-field | 210 (84.3%) | 113 (76.4%) | 319.8 (81.7%) | 330.1 (81.7%) | ||
| Three-field | 39 (15.7%) | 35 (23.6%) | 71.9 (18.3%) | 74.1 (18.3%) | ||
| Surgical procedure | 0.953 | 0.959 | ||||
| McKeown | 225 (90.4%) | 134 (90.5%) | 353.4 (90.2%) | 365.5 (90.4%) | ||
| Ivor Lewis | 24 (9.6%) | 14 (9.5%) | 38.2 (9.8%) | 38.8 (9.6%) | ||