Table 5.
Comparison of patient characteristics according to surgical treatment before and after propensity score matching (PSM).
| Characteristics | Unmatched Cohort | 1:1 Propensity Score Matched (PSM) Cohort | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Surgery Not Given | Surgery | Unadjusted | Surgery Not Given | Surgery | PSM-Adjusted | |||||
| N = 676 | % | N = 222 | % | p Value | N = 209 | % | N = 209 | % | p Value | |
| Age at diagnosis | *** | 0.089 | ||||||||
| <50 | 74 | 10.95% | 67 | 30.18% | 36 | 17.22% | 56 | 26.79% | ||
| 50–59 | 174 | 25.74% | 71 | 31.98% | 77 | 36.84% | 69 | 33.01% | ||
| 60–69 | 191 | 28.25% | 57 | 25.68% | 70 | 33.49% | 57 | 27.27% | ||
| 70–79 | 149 | 22.04% | 23 | 10.36% | 18 | 8.61% | 23 | 11.00% | ||
| 80+ | 88 | 13.02% | 4 | 1.80% | 8 | 3.83% | 4 | 1.91% | ||
| Subtype | *** | 0.894 | ||||||||
| HR+/HER2− | 283 | 41.86% | 88 | 39.64% | 79 | 37.80% | 84 | 40.19% | ||
| HR+/HER2+ | 70 | 10.36% | 37 | 16.67% | 34 | 16.27% | 37 | 17.70% | ||
| HR−/HER2+ | 51 | 7.54% | 25 | 11.26% | 20 | 9.57% | 22 | 10.53% | ||
| HR−/HER2− | 99 | 14.64% | 45 | 20.27% | 47 | 22.49% | 40 | 19.14% | ||
| unknown | 173 | 25.59% | 27 | 12.16% | 29 | 13.88% | 26 | 12.44% | ||
| Race | 0.303 | 0.112 | ||||||||
| white | 555 | 82.10% | 171 | 77.03% | 149 | 71.29% | 161 | 77.03% | ||
| black | 68 | 10.06% | 26 | 11.71% | 37 | 17.70% | 25 | 11.96% | ||
| other | 49 | 7.25% | 24 | 10.81% | 20 | 9.57% | 23 | 11.00% | ||
| unknown | 4 | 0.59% | 1 | 0.45% | 3 | 1.44% | 0 | 0.00% | ||
| Histological type | *** | 0.671 | ||||||||
| IDC | 165 | 24.41% | 109 | 49.10% | 91 | 43.54% | 100 | 47.85% | ||
| ILC | 71 | 10.50% | 5 | 2.25% | 5 | 2.39% | 5 | 2.39% | ||
| other | 440 | 65.09% | 108 | 48.65% | 113 | 54.07% | 104 | 49.76% | ||
| Marital status | 0.075 | 0.995 | ||||||||
| married | 322 | 47.63% | 128 | 57.66% | 118 | 56.46% | 119 | 56.94% | ||
| divorcedsSeparated/other | 111 | 16.42% | 30 | 13.51% | 27 | 12.92% | 28 | 13.40% | ||
| single | 102 | 15.09% | 32 | 14.41% | 31 | 14.83% | 32 | 15.31% | ||
| widowed | 119 | 17.60% | 25 | 11.26% | 27 | 12.92% | 24 | 11.48% | ||
| unknown | 22 | 3.25% | 7 | 3.15% | 6 | 2.87% | 6 | 2.87% | ||
| N stage | *** | 0.688 | ||||||||
| N0 | 166 | 24.56% | 6 | 2.70% | 4 | 1.91% | 6 | 2.87% | ||
| N1 | 331 | 48.96% | 145 | 65.32% | 144 | 68.90% | 136 | 65.07% | ||
| N2 | 38 | 5.62% | 37 | 16.67% | 26 | 12.44% | 33 | 15.79% | ||
| N3 | 70 | 10.36% | 34 | 15.32% | 35 | 16.75% | 34 | 16.27% | ||
| unknown | 71 | 10.50% | 0 | 0.00% | 0 | 0.00% | 0 | 0.00% | ||
| Grade | *** | 0.321 | ||||||||
| well | 2 | 0.30% | 4 | 1.80% | 2 | 0.96% | 4 | 1.91% | ||
| moderately | 15 | 2.22% | 13 | 5.86% | 6 | 2.87% | 12 | 5.74% | ||
| poorly | 71 | 10.50% | 56 | 25.23% | 43 | 20.57% | 48 | 22.97% | ||
| unknown | 588 | 86.98% | 149 | 67.12% | 158 | 75.60% | 145 | 69.38% | ||
| Median household income (inflation adjusted) | 0.659 | 0.437 | ||||||||
| <45,000$ | 49 | 7.25% | 19 | 8.56% | 14 | 6.70% | 18 | 8.61% | ||
| 45,000–54,999$ | 87 | 12.87% | 34 | 15.32% | 21 | 10.05% | 32 | 15.31% | ||
| 55,000–64,999$ | 159 | 23.52% | 55 | 24.77% | 53 | 25.36% | 53 | 25.36% | ||
| 65,000–74,999$ | 157 | 23.22% | 51 | 22.97% | 54 | 25.84% | 47 | 22.49% | ||
| >74,999$ | 224 | 33.14% | 63 | 28.38% | 67 | 32.06% | 59 | 28.23% | ||
| Chemothrapy | *** | 0.466 | ||||||||
| no/unknown | 295 | 43.64% | 24 | 10.81% | 30 | 14.35% | 24 | 11.48% | ||
| yes | 381 | 56.36% | 198 | 89.19% | 179 | 85.65% | 185 | 88.52% | ||
| Radiotherapy | *** | 0.768 | ||||||||
| no/unknown | 407 | 60.21% | 96 | 43.24% | 90 | 43.06% | 94 | 44.98% | ||
| yes | 269 | 39.79% | 126 | 56.76% | 119 | 56.94% | 115 | 55.02% | ||
| Bone metastases | *** | 1 | ||||||||
| no | 393 | 58.14% | 216 | 97.30% | 205 | 98.09% | 203 | 97.13% | ||
| yes | 265 | 39.20% | 3 | 1.35% | 1 | 0.48% | 3 | 1.44% | ||
| unknown | 18 | 2.66% | 3 | 1.35% | 3 | 1.44% | 3 | 1.44% | ||
| Liver metastases | *** | 0.604 | ||||||||
| no | 576 | 85.21% | 218 | 98.20% | 206 | 98.56% | 205 | 98.09% | ||
| yes | 79 | 11.69% | 1 | 0.45% | 1 | 0.48% | 1 | 0.48% | ||
| unknown | 21 | 3.11% | 3 | 1.35% | 3 | 1.44% | 3 | 1.44% | ||
| Lung metastases | *** | 0.6 | ||||||||
| no | 568 | 84.02% | 216 | 97.30% | 200 | 95.69% | 203 | 97.13% | ||
| yes | 86 | 12.72% | 3 | 1.35% | 6 | 2.87% | 3 | 1.44% | ||
| unknown | 22 | 3.25% | 3 | 1.35% | 3 | 1.44% | 3 | 1.44% | ||
| Brain metastases | ** | 0.784 | ||||||||
| no | 617 | 91.27% | 216 | 97.30% | 205 | 98.09% | 203 | 97.13% | ||
| yes | 37 | 5.47% | 2 | 0.90% | 1 | 0.48% | 2 | 0.96% | ||
| unknown | 22 | 3.25% | 4 | 1.80% | 3 | 1.44% | 4 | 1.91% | ||
** p < 0.01, *** p < 0.001.