Table 1.
Baseline characteristics of the two treatment cohorts before and after propensity score matching
| Variables | Before PSM | After PSM | ||||||
|---|---|---|---|---|---|---|---|---|
| n | Non-RT (%) | RT (%) | P | n | Non-RT (%) | RT (%) | P | |
| Age (years) | ||||||||
| 65–69 | 681 | 123 (10.0) | 558 (25.5) | < 0.001 | 244 | 122 (12.1) | 122 (12.1) | 1 |
| 70–74 | 840 | 210 (17.1) | 630 (28.8) | 420 | 210 (20.8) | 210 (20.8) | ||
| 75–79 | 803 | 251 (20.5) | 552 (25.2) | 490 | 245 (24.3) | 245 (24.3) | ||
| > 79 | 1092 | 641 (52.3) | 451 (20.6) | 866 | 433 (42.9) | 433 (42.9) | ||
| Race/ethnicity | ||||||||
| Non-Hispanic White | 2829 | 1035 (84.5) | 1794 (81.9) | 0.039 | 1694 | 847 (83.9) | 847 (83.9) | 1 |
| Non-Hispanic Black | 214 | 76 (6.2) | 138 (6.3) | 116 | 58 (5.7) | 58 (5.7) | ||
| Hispanic (All Races) | 199 | 69 (5.6) | 130 (5.9) | 122 | 61 (6.0) | 61 (6.0) | ||
| Other | 174 | 45 (3.7) | 128 (5.9) | 88 | 44 (4.4) | 44 (4.4) | ||
| Grade | ||||||||
| Well-differentiated | 2279 | 837 (68.3) | 1442 (65.8) | 0.314 | 1358 | 679 (67.2) | 679 (67.2) | 1 |
| Moderately differentiated | 1047 | 356 (29.1) | 691 (31.5) | 622 | 311 (30.8) | 311 (30.8) | ||
| Poorly differentiated/undifferentiated | 90 | 32 (2.6) | 58 (2.6) | 40 | 20 (2.0) | 20 (2.0) | ||
| Tumor stage | ||||||||
| T1 | 2848 | 1000 (81.6) | 1848 (84.3) | 0.041 | 1672 | 836 (82.8) | 836 (82.8) | 1 |
| T2 | 568 | 225 (18.4) | 343 (15.7) | 348 | 174 (17.2) | 174 (17.2) | ||
| Chemotherapy | ||||||||
| No/unknown | 3343 | 1213 (99.0) | 2130 (97.2) | < 0.001 | 2000 | 1000 (99.0) | 1000 (99.0) | 1 |
| Yes | 73 | 12 (1.0) | 61 (2.8) | 20 | 10 (1.0) | 10 (1.0) | ||
PSM propensity score matching; RT radiotherapy