Table 2 Distribution characteristics of covariates in patients who are anemic and non-anemic patients before and after propensity score matching
covariate | Before matching | After matching | ||||||
|---|---|---|---|---|---|---|---|---|
Non anemia | Anemia | X2/t/Z | p value | Non anemia | Anemia | X2/t/Z | p value | |
N = 366 | N = 335 | N = 258 | N = 258 | |||||
General information, complications | ||||||||
 Gender, no.(%) | ||||||||
  Male | 138 (37.70) | 134 (40.00%) | 0.388 | 0.533 | 96 (37.21%) | 94 (38.43%) | 0.033 | 0.855 |
  Female | 228 (62.30) | 201 (60.00%) |  | 162 (62.79%) | 164 (63.57%) |  | ||
 Age-group(y), no.(%) | ||||||||
   ≤ 60 | 97 (26.50%) | 104 (31.04%) | 5.398 | 0.067 | 72 (27.91%) | 80 (31.01%) | 4.275 | 0.118 |
  60–70 | 68 (18.58) | 42 (12.54%) |  |  | 49 (18.99%) | 32 (12.40%) |  |  |
  >70 | 201 (54.92%) | 189 (56.42%) |  | 137 (53.10%) | 146 (56.59%) |  | ||
 BMI (Kg/m2), no.(%) | ||||||||
   ≤ 18 | 39 (10.66%) | 52 (15.52%) | 4.898 | 0.086 | 34 (13.18%) | 40 (15.50%) | 0.634 | 0.728 |
  18–25 | 260 (71.04%) | 235 (70.15%) |  | 185 (71.71%) | 178 (68.99%) |  | ||
  >25 | 67 (18.30%) | 48 (14.33%) |  |  | 39 (15.12%) | 40 (15.50%) |  |  |
 ASA classification, no.(%) | ||||||||
   ≤ 2 | 100 (27.32%) | 70 (20.90%) | 3.933 | 0.047 | 61 (23.64%) | 60 (23.26%) | 0.011 | 0.917 |
  >2 | 266 (72.68%) | 265 (79.10%) |  | 197 (76.36%) | 198 (76.74%) |  | ||
 Smoking history, no.(%) | ||||||||
  No | 283 (77.32%) | 265 (79.10%) | 0.326 | 0.568 | 211 (81.78%) | 206 (79.84%) | 0.312 | 0.576 |
  Yes | 83 (22.68%) | 70 (20.90%) |  | 47 (18.22%) | 52 (20.16%) |  |  | |
 Drinking history, no.(%) | ||||||||
  No | 302 (82.51%) | 274 (81.79%) | 0.062 | 0.803 | 216 (83.72%) | 216 (83.72%) | 0 | 1 |
  Yes | 64 (17.49%) | 61 (18.21%) |  | 42 (16.28%) | 42 (16.28%) |  | ||
 Cerebral infarction, no.(%) | ||||||||
  No | 318 (86.89%) | 285 (85.1%) | 0.477 | 0.49 | 222 (86.05%) | 221 (85.66%) | 0.016 | 0.899 |
  Yes | 48 (13.11%) | 50 (14.9%) |  | 36 (13.95%) | 37 (14.34%) |  |  | |
 Diabetes, no.(%) | ||||||||
  No | 288 (78.7%) | 280 (83.58%) | 2.725 | 0.099 | 214 (82.95%) | 212 (82.17%) | 0.054 | 0.817 |
  Yes | 78 (21.3%) | 55 (16.42%) |  | 44 (17.05%) | 46 (17.83%) |  | ||
 Coronary heart disease, no.(%) | ||||||||
  No | 327 (89.34%) | 292 (87.16%) | 0.805 | 0.37 | 232 (89.92%) | 226 (87.60%) | 0.699 | 0.403 |
  Yes | 39 (10.66%) | 43 (12.84%) |  | 26 (10.08%) | 32 (2.40%) |  |  | |
 Hypertension, no.(%) | ||||||||
  No | 238 (65.02%) | 234 (69.85%) | 1.85 | 0.174 | 181 (70.16%) | 175 (67.83%) | 0.326 | 0.568 |
  Yes | 128 (35.98%) | 101 (30.15%) |  | 72 (29.84%) | 83 (32.17%) |  |  | |
 Hyperlipidemia, no.(%) | ||||||||
  No | 347 (94.81%) | 328 (97.91%) | 4.712 | 0.03 | 252 (97.67%) | 251 (97.29%) | 0.079 | 0.797 |
  Yes | 19 (5.19%) | 7 (2.09%) |  |  | 6 (2.33%) | 7 (2.71%) |  |  |
 Pulmonary diseases, no.(%) | ||||||||
  No | 325 (88.80%) | 288 (85.97%) | 1.274 | 0.259 | 223 (86.43%) | 226 (97.29%) | 0.154 | 0.694 |
  Yes | 41 (11.20%) | 47 (14.03%) |  |  | 35 (13.57%) | 32 (12.40%) |  |  |
 Hepatic diseases, no.(%) | ||||||||
  No | 309 (84.43%) | 301 (89.85%) | 4.556 | 0.033 | 236 (91.47%) | 232 (89.92%) | 0.368 | 0.544 |
  Yes | 57 (15.57%) | 34 (10.15%) |  |  | 22 (8.53%) | 26 (10.08%) |  |  |
 Renal diseases, no.(%) | ||||||||
  No | 328 (89.62%) | 289 (86.27%) | 1.86 | 0.173 | 229 (88.76%) | 228 (88.37%) | 0.019 | 0.89 |
  Yes | 38 (10.38%) | 46 (13.73%) |  |  | 29 (11.24%) | 30 (11.63%) |  | |
 Malignant tumor, no.(%) | ||||||||
  No | 339 (92.62%) | 311 (92.84%) | 0.012 | 0.914 | 235 (91.09%) | 240 (93.02%) | 0.662 | 0.416 |
  Yes | 27 (7.38%) | 24 (7.16%) |  |  | 23 (8.91%) | 18 (6.98%) |  |  |
 Hypoproteinemia, no.(%) | ||||||||
  No | 307 (83.88%) | 222 (66.27%) | 29.298 | <0.001 | 200 (77.52%) | 198 (76.74%) | 0.044 | 0.834 |
  Yes | 59 (16.12%) | 113 (33.73%) |  | 58 (22.48%) | 60 (23.26%) |  |  | |
 Anticoagulation, no.(%) | ||||||||
  No | 13 (3.55%) | 20 (5.63%) | 2.28 | 0.131 | 13 (5.04%) | 14 (5.43%) | 0.039 | 0.843 |
  Yes | 353 (96.45%) | 315 (94.37%) |  | 245 (94.96%) | 244 (94.57%) |  | ||
 Duration of surgery (h), no.(%) | ||||||||
   ≤ 2 | 257 (70.22%) | 208 (62.09%) | 5.176 | 0.023 | 171 (66.28%) | 168 (65.12%) | 0.077 | 0.781 |
  >2 | 109 (29.78%) | 127 (37.91%) |  | 87 (33.72%) | 90 (34.88%) |  | ||
Time from trauma to surgery(d), no.(%) | ||||||||
   ≤ 7 | 142 (38.80) | 88 (26.27%) | 12.455 | <0.001 | 126 (48.84%) | 117 (45.35%) | 0.63 | 0.427 |
  >7 | 224 (61.20) | 247 (73.73%) |  | 132 (51.16%) | 141 (54.65%) |  | ||
 Blood transfusion, no.(%) | ||||||||
  No | 179 (48.91%) | 196 (58.51%) | 6.48 | 0.011 | 136 (52.17%) | 117 (45.35%) | 0.07 | 0.791 |
  Yes | 187 (51.09%) | 139 (41.49%) |  | 132 (51.16%) | 141 (54.65%) |  | ||
Test indicators | ||||||||
 WBCa(10^9/L) | 8.69 ± 2.96 | 8.08 ± 2.81 | 2.8 | 0.005 | 8.12 ± 2.63 | 8.22 ± 2.86 | 0.405 | 0.685 |
 PTa (s) | 13.51 ± 1.51 | 13.86 ± 1.65 | 2.918 | 0.002 | 13.52 ± 1.24 | 13.65 ± 1.29 | 1.192 | 0.234 |
 APTTa (s) | 36.67 ± 5.19 | 36.29 ± 6.52 | 1.387 | 0.166 | 36.76 ± 5.07 | 36.85 ± 6.57 | 0.163 | 0.871 |
PLTa (10^9/L) | 167 | 168.5 | 0.069 | 0.945 | 170 | 169.50 | 0.717 | 0.473 |
(109.70,213.25) | (134.00,213.00) | Â | (135.00,213.25) | (125.75,214.00) | Â | |||
Creaa (mmol/L) | 67 | 66 | 0.473 | 0.636 | 66 | 66 | 0.386 | 0.7 |
(47.70,78.00) | (47.60,83.00) | Â | (55.00,79.00) | (56.00,81.25) | Â | |||
NEUT%a (%) | 75.45 | 75 | 0.478 | 0.633 | 74.4 | 75.1 | 1.44 | 0.15 |
(63.37,80.93) | (61.00,80.80) | Â | (68.23,80.15) | (70.10,80.13) | Â | |||