Table 5.
Comparison of patient characteristics according to surgery treatment before and after propensity score matching (PSM)
| Characteristics | Unmatched Cohort | 1:1 propensity score matched (PSM) Cohort | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Surgery | Surgery not given | Unadjusted | Surgery | Surgery not given | PSM-adjusted | |||||
| N = 234 | % | N = 1699 | % | P value | N = 200 | % | N = 200 | % | P value | |
| Age at diagnosis | 0.004 | 0.951 | ||||||||
| < 40 | 24 | 10.26 | 117 | 6.89 | 19 | 9.50 | 18 | 9.00 | ||
| 40–49 | 41 | 17.52 | 210 | 12.36 | 34 | 17.00 | 32 | 16.00 | ||
| 50–59 | 72 | 30.77 | 457 | 26.90 | 60 | 30.00 | 59 | 29.50 | ||
| 60–69 | 57 | 24.36 | 519 | 30.55 | 49 | 24.50 | 50 | 25.00 | ||
| 70–79 | 23 | 9.83 | 284 | 16.72 | 23 | 11.50 | 29 | 14.50 | ||
| 80 + | 17 | 7.26 | 112 | 6.59 | 15 | 7.50 | 12 | 6.00 | ||
| Subtype | < 0.001 | 0.815 | ||||||||
| HR + /HER2- | 85 | 36.32 | 632 | 37.20 | 75 | 37.50 | 68 | 34.00 | ||
| HR + /HER2 + | 33 | 14.10 | 275 | 16.19 | 30 | 15.00 | 29 | 14.50 | ||
| HR-/HER2 + | 29 | 12.39 | 210 | 12.36 | 26 | 13.00 | 29 | 14.50 | ||
| HR-/HER2- | 64 | 27.35 | 269 | 15.83 | 48 | 24.00 | 46 | 23.00 | ||
| Unknown | 23 | 9.83 | 313 | 18.42 | 21 | 10.50 | 28 | 14.00 | ||
| Race | 0.830 | 0.786 | ||||||||
| White | 172 | 73.50 | 1275 | 75.04 | 143 | 71.50 | 148 | 74.00 | ||
| Black | 38 | 16.24 | 269 | 15.83 | 34 | 17.00 | 33 | 16.50 | ||
| Other | 24 | 10.26 | 155 | 9.12 | 23 | 11.50 | 19 | 9.50 | ||
| Histological type | < 0.001 | 0.700 | ||||||||
| IDC | 177 | 75.64 | 1082 | 63.68 | 149 | 74.50 | 149 | 74.50 | ||
| ILC | 11 | 4.70 | 86 | 5.06 | 10 | 5.00 | 6 | 3.00 | ||
| Mixed | 12 | 5.13 | 58 | 3.41 | 10 | 5.00 | 9 | 4.50 | ||
| Other | 34 | 14.53 | 473 | 27.84 | 31 | 15.50 | 36 | 18.00 | ||
| Marital status | 0.132 | 0.623 | ||||||||
| Married | 105 | 44.87 | 685 | 40.32 | 86 | 43.00 | 81 | 40.50 | ||
| Single | 64 | 27.35 | 430 | 25.31 | 56 | 28.00 | 52 | 26.00 | ||
| Others | 65 | 27.78 | 584 | 34.37 | 58 | 29.00 | 67 | 33.50 | ||
| T stage | < 0.001 | 0.802 | ||||||||
| T1 | 34 | 14.53 | 162 | 9.54 | 25 | 12.50 | 28 | 14.00 | ||
| T2 | 69 | 29.49 | 343 | 20.19 | 53 | 26.50 | 48 | 24.00 | ||
| T3 | 31 | 13.25 | 217 | 12.77 | 29 | 14.50 | 23 | 11.50 | ||
| T4 | 84 | 35.90 | 556 | 32.73 | 77 | 38.50 | 86 | 43.00 | ||
| Tx | 16 | 6.84 | 421 | 24.78 | 16 | 8.00 | 15 | 7.50 | ||
| Grade | < 0.001 | 0.923 | ||||||||
| Well | 9 | 3.85 | 58 | 3.41 | 8 | 4.00 | 7 | 3.50 | ||
| Moderately | 52 | 22.22 | 396 | 23.31 | 48 | 24.00 | 43 | 21.50 | ||
| Poorly | 146 | 62.39 | 610 | 35.90 | 117 | 58.50 | 121 | 60.50 | ||
| Unknown | 27 | 11.54 | 635 | 37.37 | 27 | 13.50 | 29 | 14.50 | ||
| Median household income (inflation adjusted) | 0.093 | 0.944 | ||||||||
| < 40,000$ | 19 | 8.12 | 85 | 5.00 | 15 | 7.50 | 14 | 7.00 | ||
| 40,000–49,999$ | 30 | 12.82 | 189 | 11.12 | 24 | 12.00 | 28 | 14.00 | ||
| 50,000–59,999$ | 41 | 17.52 | 251 | 14.77 | 35 | 17.50 | 30 | 15.00 | ||
| 60,000–69,999$ | 76 | 32.48 | 566 | 33.31 | 63 | 31.50 | 63 | 31.50 | ||
| 70,000$ + | 68 | 29.06 | 608 | 35.79 | 63 | 31.50 | 65 | 32.50 | ||
| Chemotherapy | < 0.001 | 0.586 | ||||||||
| No/unknown | 66 | 28.21 | 812 | 47.79 | 63 | 31.50 | 58 | 29.00 | ||
| Yes | 168 | 71.79 | 887 | 52.21 | 137 | 68.50 | 142 | 71.00 | ||
| Radiotherapy | < 0.001 | 0.517 | ||||||||
| No/unknown | 60 | 25.64 | 697 | 41.02 | 59 | 29.50 | 65 | 32.50 | ||
| Yes | 174 | 74.36 | 1002 | 58.98 | 141 | 70.50 | 135 | 67.50 | ||
| Liver metastases | < 0.001 | 0.370 | ||||||||
| No/unknown | 193 | 82.48 | 1096 | 64.51 | 159 | 79.50 | 166 | 83.00 | ||
| Yes | 41 | 17.52 | 603 | 35.49 | 41 | 20.50 | 34 | 17.00 | ||
| Lung metastases | 0.002 | 0.918 | ||||||||
| No/unknown | 154 | 65.81 | 938 | 55.21 | 124 | 62.00 | 123 | 61.50 | ||
| Yes | 80 | 34.19 | 761 | 44.79 | 76 | 38.00 | 77 | 38.50 | ||