Table 1 Clinical characteristics of the patients before and after propensity score matching
Unmatched comparison | Matched comparison | ||||||||||||
Without AC (n = 181) | With AC (n = 37) | p | SMD | Without AC (n = 25) | With AC (n = 25) | p | SMD | ||||||
Covariates | Category | N | % | N | % | N | % | N | % | ||||
Age | < 70 | 86 | 48% | 17 | 46% | 0.86 | 0.03 | 12 | 48% | 12 | 48% | 1.00 | < 0.001 |
≥ 70 | 95 | 52% | 20 | 54% | 13 | 52% | 13 | 52% | |||||
Sex | Male | 90 | 50% | 18 | 49% | 0.90 | 0.02 | 15 | 60% | 11 | 44% | 0.25 | 0.32 |
Female | 91 | 50% | 19 | 51% | 10 | 40% | 14 | 56% | |||||
ASA-PS | 1 or 2 | 167 | 92% | 29 | 78% | 0.01 | 0.40 | 16 | 64% | 18 | 72% | 0.54 | 0.17 |
3 or 4 | 14 | 8% | 8 | 22% | 9 | 36% | 7 | 28% | |||||
TNM classification (UICC 8th edition) | |||||||||||||
T | 0 or 1 | 76 | 42% | 18 | 49% | 0.23 | 0.30 | 8 | 32% | 10 | 40% | 0.47 | 0.35 |
2 | 92 | 51% | 14 | 38% | 15 | 60% | 11 | 44% | |||||
3 or 4 | 13 | 7% | 5 | 13% | 2 | 8% | 4 | 16% | |||||
N | 0 | 155 | 86% | 28 | 76% | 0.13 | 0.08 | 20 | 80% | 17 | 68% | 0.33 | 0.28 |
≥ 1 | 26 | 14% | 9 | 24% | 5 | 20% | 8 | 32% | |||||
M | 0 | 181 | 100% | 37 | 100% | 25 | 100% | 25 | 100% | ||||
Stage | 0 or 1 or 2 | 149 | 82% | 27 | 73% | 0.19 | 0.23 | 20 | 80% | 17 | 68% | 0.33 | 0.28 |
3 or 4 | 32 | 18% | 10 | 27% | 5 | 20% | 8 | 32% | |||||
Lymph node dissection | D0 | 41 | 23% | 17 | 46% | 0.004 | 0.51 | 9 | 36% | 10 | 40% | 0.77 | 0.08 |
D1 or D2 | 140 | 77% | 20 | 54% | 16 | 64% | 15 | 60% | |||||
Intraoperative bile spillage | Negative | 164 | 91% | 15 | 41% | < 0.001 | 1.24 | 15 | 60% | 14 | 56% | 0.77 | 0.08 |
Positive | 17 | 9% | 22 | 59% | 10 | 40% | 11 | 44% | |||||
Intraoperative blood loss | < 200 mL | 97 | 54% | 11 | 30% | 0.008 | 0.50 | 7 | 28% | 10 | 40% | 0.37 | 0.26 |
≥ 200 mL | 84 | 46% | 26 | 70% | 18 | 72% | 15 | 60% | |||||
Operative time (min)a | 200 (97) | 201 (97) | 0.98 | 0.01 | 206 (88) | 195 (97) | 0.66 | 0.12 | |||||
Factors not used as covariates in the propensity score matching analysis | |||||||||||||
Unmatched comparison | Matched comparison | ||||||||||||
Without AC (n = 181) | With AC (n = 37) | p | SMD | Without AC (n = 25) | With AC (n = 25) | p | SMD | ||||||
Covariates | Category | N | % | N | % | N | % | N | % | ||||
Laparoscopic surgery | No | 148 | 82% | 28 | 76% | 0.39 | 0.005 | 22 | 88% | 22 | 88% | 1.0 | < 0.001 |
Yes | 33 | 18% | 9 | 24% | 3 | 12% | 3 | 12% | |||||
Incidental GBC | Negative | 133 | 73% | 3 | 8% | < 0.001 | 1.78 | 11 | 44% | 1 | 4% | 0.001 | 0.887 |
Positive | 48 | 27% | 34 | 92% | 14 | 56% | 24 | 96% | |||||
Preoperative diagnosis of suspected GBC | No | 54 | 30% | 33 | 89% | < 0.001 | 1.52 | 13 | 52% | 22 | 88% | 0.012 | 0.80 |
Yes | 127 | 70% | 4 | 11% | 12 | 48% | 3 | 12% | |||||