Patient demographic and clinical characteristics
| Before matching | After matching | |||||
| EA group (n=449) | Non-EA group (n=2299) | Standardised difference | EA group (n=406) | Non-EA group (n=812) | Standardised difference | |
| Age, year | 69±14 | 68±13 | 8.0 | 69±14 | 69±13 | 3.8 |
| Sex, male | 288 (64.1%) | 1409 (61.3%) | 5.9 | 264 (65.0%) | 523 (64.4%) | 1.3 |
| ASA class ≥3 | 170 (37.9%) | 824 (35.8%) | 4.2 | 155 (38.2%) | 301 (37.1%) | 2.3 |
| BMI, kg/m2 | 24.1±3.7 | 24.1±3.8 | 0.7 | 24.1±3.7 | 24.0±3.7 | 3.0 |
| Comorbidites | ||||||
| Diabetes | 85 (18.9%) | 530 (23.1%) | 10.1 | 81 (20.0%) | 174 (21.4%) | 3.6 |
| Coronary artery disease | 57 (12.7%) | 295 (12.8%) | 0.4 | 54 (13.3%) | 110 (13.5%) | 0.7 |
| Heart failure | 39 (8.7%) | 156 (6.8%) | 7.1 | 34 (8.4%) | 59 (7.3%) | 4.1 |
| Stroke | 22 (4.9%) | 142 (6.2%) | 5.6 | 21 (5.2%) | 44 (5.4%) | 1.1 |
| Chronic kidney disease | 61 (13.6%) | 349 (15.2%) | 4.5 | 58 (14.3%) | 117 (14.4%) | 0.4 |
| Pretreatment CEA, μg/L | 2.82 (2.16 to 4.62) | 2.78 (2.00 to 5.57) | 6.8 | 2.81 (2.16 to 4.61) | 2.91 (2.06 to 6.01) | 1.3 |
| Anaesthesia time, min | 270 (225 to 330) | 285 (240 to 345) | 18.7 | 270 (225 to 330) | 270 (240 to 330) | 10.4 |
| Blood transfusion | 127 (28.3%) | 602 (26.2%) | 4.7 | 113 (27.8%) | 233 (28.7%) | 1.9 |
| Tumour location, right sided | 199 (44.3%) | 944 (41.1%) | 6.6 | 174 (42.9%) | 340 (41.9%) | 2.0 |
| Laparoscopic surgery | 10 (2.2%) | 215 (9.4%) | 30.9 | 10 (2.5%) | 22 (2.7%) | 1.6 |
| Preoperative C/T±R/T | 2 (0.4%) | 11 (0.5%) | 0.5 | 2 (0.5%) | 4 (0.5%) | 0 |
| Postoperative C/T (<90 days) | 176 (39.2%) | 1080 (47.0%) | 15.8 | 156 (38.4%) | 329 (40.5%) | 4.3 |
| Postoperative R/T (<90 days) | 4 (0.9%) | 8 (0.3%) | 6.9 | 2 (0.5%) | 4 (0.5%) | 0 |
| Follow-up interval, month | 71.3 (37.8 to 120.7) | 42.8 (24.3 to 66.8) | 58.0 | 71.0 (37.8 to 101.1) | 48.2 (27.7 to 73.0) | 45.4 |
Values were mean±SD, counts (per cent) or median (IQR). Continuous variables were analysed with either t-tests or Wilcoxon rank sum tests, as appropriate; categorical variables were analysed with Pearson χ2 tests. Standardised difference is the difference in mean, proportion or rank divided by the pooled SE, expressed as percentage.
ASA, American Society of Anesthesiologists; BMI, body mass index; CEA, carcinoembryonic antigen; C/T, chemotherapy; R/T, radiotherapy.