Table 1 Baseline characteristics of the two groups and imbalance between the original (unweighted) and propensity score—weighted groups
Characteristic | Level | Spinal anaesthesia (ITM + 0.25% bupivacaine) | Propensity weighting | ||
|---|---|---|---|---|---|
No | Yes | SMD (%; before) | SMD (%; after) | ||
n | 40 | 26 | |||
Gender (%) | F | 24 (60.0) | 14 (53.8) | 12.5 | 10.0 |
M | 16 (40.0) | 12 (46.2) | |||
Age (mean (SD)) | 48.77 (12.82) | 52.42 (13.17) | 28.1 | 6.0 | |
ASA grade (%) | 1 | 19 (47.5) | 14 (53.8) | 12.7 | 7.7 |
2 | 19 (47.5) | 10 (38.5) | − 18.3 | − 9.4 | |
3 | 2 (5.0) | 2 (7.7) | 11.1 | 3.3 | |
Levels (%) | 1 | 17 (42.5) | 11 (42.3) | 10.7 | 8.1 |
2 | 22 (55.0) | 12 (46.2) | |||
3 | 0 (0.0) | 2 (7.7) | |||
4 | 0 (0.0) | 1 (3.8) | |||
5 | 1 (2.5) | 0 (0.0) | |||