Table 1. Baseline characteristics according to hospital volume and surgeon volume (n = 13159).
| Variable | High-volume hospital | Low-volume hospital | P value | ||||||
| High-volumesurgeon (n = 3830) | Low-volume surgeon (n = 3035) | High-volume surgeon (n = 1010) | Low-volume surgeon (n = 5284) | ||||||
| n (%) | n (%) | n (%) | n (%) | ||||||
| Age, years (mean ±SD) | 55.06±13.95 | 56.56±15.08 | 57.17±12.96 | 58.00±14.50 | <0.001 | ||||
| Gender | 0.002 | ||||||||
| Male | 2561 | (66.9) | 1926 | (63.5) | 637 | (63.1) | 3347 | (63.3) | |
| Female | 1269 | (33.1) | 1109 | (36.5) | 373 | (36.9) | 1937 | (36.7) | |
| Indication for surgery | <0.001 | ||||||||
| Hepatocellular carcinoma | 2667 | (69.6) | 1718 | (56.6) | 621 | (61.5) | 3046 | (57.6) | |
| Cholangiocarcinoma | 166 | (4.3) | 143 | (4.7) | 51 | (5.0) | 276 | (5.2) | |
| Metastatic malignancy | 159 | (4.2) | 441 | (14.5) | 74 | (7.3) | 486 | (9.2) | |
| Benign disease | 838 | (21.9) | 733 | (24.2) | 264 | (26.1) | 1476 | (27.9) | |
| Surgical procedure | 0.007 | ||||||||
| Lobectomy or more | 983 | (25.7) | 732 | (24.1) | 232 | (23.0) | 1423 | (26.9) | |
| < Lobectomy | 2847 | (74.3) | 2303 | (75.9) | 778 | (77.0) | 3861 | (73.1) | |
| With hepatitis/cirrhosis | 1629 | (42.5) | 1113 | (36.7) | 423 | (41.9) | 1992 | (37.7) | <0.001 |
| Pre-operative cirrhosis-related complication | 352 | (9.2) | 281 | (9.3) | 90 | (8.9) | 679 | (12.9) | <0.001 |
| Post-operative cirrhosis-related complication | 166 | (4.3) | 140 | (4.6) | 47 | (4.7) | 331 | (6.3) | <0.001 |
| Comorbidity | |||||||||
| Hypertension | 440 | (11.5) | 433 | (14.3) | 135 | (13.4) | 725 | (13.7) | 0.003 |
| Ischemic heart disease | 38 | (1.0) | 52 | (1.7) | 12 | (1.2) | 95 | (1.8) | 0.009 |
| Arrhythmia | 33 | (0.9) | 34 | (1.1) | 5 | (0.5) | 68 | (1.3) | 0.066 |
| Heart failure | 5 | (0.1) | 18 | (0.6) | 3 | (0.3) | 24 | (0.5) | 0.012 |
| Cerebrovascular disease | 14 | (0.4) | 23 | (0.8) | 6 | (0.6) | 58 | (1.1) | 0.001 |
| COPD and associated condition | 30 | (0.8) | 31 | (1.0) | 8 | (0.8) | 69 | (1.3) | 0.085 |
| Renal disease | 43 | (1.1) | 83 | (2.7) | 18 | (1.8) | 147 | (2.8) | <0.001 |
| Diabetes | 364 | (9.5) | 384 | (12.7) | 125 | (12.4) | 733 | (13.9) | <0.001 |
| Socioeconomic status | <0.001 | ||||||||
| High | 1051 | (27.4) | 651 | (21.4) | 220 | (21.8) | 911 | (17.2) | |
| Moderate | 1439 | (37.6) | 1163 | (38.3) | 433 | (42.9) | 2308 | (43.7) | |
| Low | 1340 | (35.0) | 1221 | (40.2) | 357 | (35.3) | 2065 | (39.1) | |
| Geographic region | <0.001 | ||||||||
| Northern | 1872 | (48.9) | 1393 | (45.9) | 413 | (40.9) | 2311 | (43.7) | |
| Central | 730 | (19.1) | 591 | (19.7) | 185 | (18.3) | 922 | (17.4) | |
| Southern/Eastern | 1228 | (32.1) | 1045 | (34.4) | 412 | (40.8) | 2051 | (38.8) | |
| Urbanization level of residence | <0.001 | ||||||||
| Urban | 1212 | (31.6) | 1013 | (33.4) | 298 | (29.5) | 1188 | (22.5) | |
| Suburban | 1586 | (41.4) | 1253 | (41.3) | 421 | (41.7) | 2254 | (42.7) | |
| Rural | 1032 | (26.9) | 769 | (25.3) | 291 | (28.8) | 1842 | (34.9) | |
Abbreviation: SD, standard deviation; COPD, chronic obstructive pulmonary disease.