Table 4. Comparisons of surgical outcomes and postoperative pain between RATS and VATS before and after IPTW adjustment.
| Variables | Before IPTW adjustment | After IPTW adjustment | |||||
|---|---|---|---|---|---|---|---|
| RATS (n=20) | VATS (n=37) | P value | RATS (n=20) | VATS (n=37) | P value | ||
| Primary outcomes | |||||||
| B duration (days)a | 2 (1 to 4) | 3 (1 to 7) | <0.001 | 2 (1 to 4) | 3 (1 to 7) | <0.001 | |
| CIII duration (days)a | 3 (1 to 6) | 5 (1 to 14) | 0.018 | 3 (1 to 6) | 5 (1 to 14) | 0.037 | |
| Secondary outcomes | |||||||
| Operation time (minutes) | 176 (103 to 285) | 143 (68 to 385) | 0.024 | 176 (103 to 285) | 143 (68 to 385) | 0.025 | |
| Intraoperative bleeding (mL) | 10 (5 to 100) | 10 (5 to 390) | 0.328 | 10 (5 to 100) | 10 (5 to 390) | 0.332 | |
| Pleural drainage duration (days) | 1 (1 to 2) | 1 (1 to 6) | 0.065 | 1 (1 to 2) | 1 (1 to 6) | 0.067 | |
| Postoperative pleural drainage (mL/kg/day) | 3.3 (0.4 to 8.0) | 4.3 (1.0 to 9.9) | 0.707 | 3.3 (0.4 to 8.0) | 4.3 (1.0 to 9.9) | 0.713 | |
| Removal of oxygen (days) | 1 (1 to 8) | 1 (1 to 7) | 0.310 | 1 (1 to 8) | 1 (1 to 7) | 0.315 | |
| Removal of urinary balloon catheter (days) | 1 (1 to 2) | 1 (1 to 3) | 0.503 | 1 (1 to 2) | 1 (1 to 3) | 0.511 | |
| Postoperative hospital stay (days) | 8 (2 to 14) | 8 (2 to 18) | 0.407 | 8 (2 to 14) | 8 (2 to 18) | 0.412 | |
| Total complications | 4 (20.0) | 8 (21.6) | 1.000 | 20.7 | 18.5 | 0.599 | |
| Phrenic nerve palsy | 3 (15.0) | 3 (8.1) | 0.657 | 13.4 | 6.6 | 0.458 | |
| Intercostal neuralgia | 1 (5.0) | 2 (5.4) | 1.000 | 7.3 | 4.6 | 1.000 | |
| Pneumothorax | 0 | 1 (2.7) | 1.000 | 0 | 1.9 | 1.000 | |
| Atrial fibrillation | 0 | 1 (2.7) | 1.000 | 0 | 1.9 | 1.000 | |
| Disrupted wound healing | 0 | 1 (2.7) | 1.000 | 0 | 3.4 | 1.000 | |
| Myasthenic crisis | 0 | 0 | – | 0 | 0 | – | |
| Mortality (30-day) | 0 | 0 | – | 0 | 0 | – | |
| Mortality (90-day) | 0 | 0 | – | 0 | 0 | – | |
| Postoperative pain | |||||||
| During hospitalization | |||||||
| Epidural analgesia | 20 | 30 | 0.045 | 100 | 84.9 | 0.018 | |
| Removal of epidural anesthesia | 2 (1 to 4) | 2 (1 to 4) | 0.144 | 2 (1 to 4) | 2 (1 to 4) | 0.146 | |
| No. of injections of analgesics | 2 (0 to 4) | 2 (1 to 5) | 0.577 | 2 (0 to 4) | 2 (1 to 5) | 0.583 | |
| Additional regular prescription | 2 | 10 | 0.182 | 14.1 | 35.5 | 0.033 | |
| Prescription as needed | 4 | 9 | 1.000 | 10.6 | 28.4 | 0.035 | |
| In the first follow-up | |||||||
| Duration (days) | 25 (12 to 37) | 22 (12 to 97) | 0.085 | 25 (12 to 37) | 22 (12 to 97) | 0.087 | |
| Pain gradeb | 0.885 | 0.376 | |||||
| 1 | 10 (50.0) | 19 (51.4) | 38.9 | 45.5 | |||
| 2 | 9 (45.0) | 15 (40.5) | 52.4 | 39.1 | |||
| 3 | 1 (5.0) | 3 (8.1) | 8.7 | 15.5 | |||
| Prescription | 10 (52.6) | 17 (46.0) | 0.779 | 53.99 | 51.5 | 0.812 | |
| In the second follow-up | |||||||
| Duration (days) | 92 (22 to 214) | 116 (48 to 389) | 0.267 | 92 (22 to 214) | 116 (48 to 389) | 0.272 | |
| Pain gradeb | 0.700 | 0.109 | |||||
| 1 | 18 (90.0) | 32 (86.5) | 86.9 | 84.0 | |||
| 2 | 1 (5.0) | 4 (10.8) | 4.4 | 14.1 | |||
| 3 | 1 (5.0) | 1 (2.7) | 8.7 | 4.9 | |||
| Prescription | 2 (10.5) | 4 (10.8) | 1.000 | 13.8 | 10.4 | 1.000 | |
Continuous data are presented as the median and interquartile range in brackets, and categorical data are presented as n (%) before IPTW adjustment, while as only % after IPTW adjustment. a, improvement in postoperative QOL was presented as the durations required to achieve a B item of fewer than 3 points (B duration) and to achieve nursing criterion CIII (CIII duration), based on the Nursing Dependency Score and Nursing Criteria, respectively; b, pain grade was defined as follows: 1. no pain or pain not requiring analgesics; 2. pain requiring analgesics (excluding those for neuralgia); 3. pain requiring analgesics for neuralgia. RATS, robot-assisted thoracoscopic surgery; VATS, video-assisted thoracoscopic surgery; IPTW, inverse probability of treatment weighting; QOL, quality of life.