Table 1.
Baseline characteristics before and after propensity score matching
| Before PS matching | After PS matching | ||||||
|---|---|---|---|---|---|---|---|
| Laparoscopic RPS (n = 171) | Open RPS (n = 228) | p value | Laparoscopic RPS (n = 150) | Open RPS (n = 150) | p value | SMD | |
| Age, < 75 years, n (%)a | 135 (78.9) | 175 (76.8) | 0.60 | 114 (76.0) | 117 (78.0) | 0.690 | 0.047 |
| Age (years)b | 64 (13.3) | 65 (13.1) | 0.82 | 64.5 (13.8) | 64.2 (13.5) | 0.801 | |
| Sex, malea | 87 (50.9) | 142 (62.3) | 0.02 | 87 (58.0) | 85 (56.7) | 0.856 | 0.027 |
| BMI (kg/m2)b | 27.5 (4.8) | 26.3 (4.9) | 0.06 | 27.5 (4.8) | 26.6 (4.8) | 0.179 | |
| ASA classificationa | 0.07 | 0.473 | 0.086 | ||||
| 1–2 | 144 (84.2) | 175 (76.8) | 123 (82.0) | 118 (78.7) | |||
| 3–4 | 27 (15.8) | 53 (23.2) | 27 (18.0) | 32 (21.3) | |||
| Previous abdominal surgery, yesa | 92 (53.8) | 113 (49.6) | 0.40 | 74 (49.3) | 71 (47.3) | 0.690 | 0.040 |
| Previous abdominal surgery | 0.11 | 0.076 | |||||
| No | 79 (46.2) | 115 (57.9) | 76 (50.7) | 79 (52.7) | |||
| Yes, only laparoscopic | 43 (25.1) | 68 (29.8) | 32 (21.3) | 46 (30.7) | |||
| Yes, open surgery | 49 (28.7) | 45 (19.7) | 42 (28.0) | 25 (16.7) | |||
| Previous liver surgery, yesa | 12 (7.0) | 16 (7.0) | 0.99 | 11 (7.3) | 10 (6.7) | 1.00 | 0.025 |
| Neoadjuvant chemotherapy, yesa | 53 (34.0) | 81 (38.0) | 0.52 | 47 (31.3) | 47 (31.3) | 1.00 | 0.0 |
| Diagnosisa | 0.61 | 0.344 | 0.082 | ||||
| Malignancy | 151 (88.3) | 205 (89.9) | 132 (88.0) | 136 (90.7) | |||
| Diagnosis | 0.67 | 0.357 | |||||
| Colorectal liver metastasis | 67 (39.2) | 103 (45.2) | 55 (36.7) | 63 (42.0) | |||
| Hepatocellular carcinoma | 56 (32.7) | 70 (30.7) | 51 (34.0) | 51 (34.0) | |||
| Other malignancy | 28 (16.4) | 32 (14.0) | 26 (17.3) | 22 (14.7) | |||
| Benign | 20 (11.7) | 23 (10.1) | 18 (12.0) | 14 (9.3) | |||
| Cirrhosisa, yes | 29 (17.0) | 33 (14.5) | 0.50 | 24 (16.0) | 25 (16.7) | 1.00 | 0.018 |
| Number of lesionsa | 0.004 | 0.815 | 0.030 | ||||
| One | 128 (74.9) | 139 (61.0) | 107 (71.3) | 109 (72.7) | |||
| Multiple | 43 (25.1) | 89 (39.0) | 43 (28.7) | 41 (27.3) | |||
Values in parentheses are percentages unless indicated otherwise
ASA American Society of Anesthesiologists, BMI Body Mass Index, RPS open right posterior sectionectomy, PS propensity score, SMD standardized mean difference
aVariables used in matching
bMean (s.d.)