Baseline characteristics compared between two groups before and after stabilized inverse probability of treatment weighting
| Variable | Before sIPTW | After sIPTW | |||||
|---|---|---|---|---|---|---|---|
| Propofol group (n = 461) | Sevoflurane group (n = 372) | SMD | Propofol group (n = 462.1) | Sevoflurane group (n = 359.2) | SMD | ||
| Female | 262 (56.8) | 186 (50.0) | 0.137 | 248.2 (53.7) | 189.5 (52.8) | 0.019 | |
| Age (yr) | 66.0 (59.0–73.0) | 67.0 (60.0–74.0) | 0.068 | 66.0 (60.0–74.0) | 67.0 (60.0–74.0) | 0.012 | |
| Body mass index (kg/m2) | 24.2 (22.2–25.9) | 23.9 (22.1–25.7) | 0.037 | 24.2 (22.1–25.9) | 24.1 (22.2–26.1) | 0.003 | |
| ASA physical status | 0.476 | 0.078 | |||||
| I | 68 (14.8) | 9 (2.4) | 42.5 (9.2) | 25.5 (7.1) | |||
| II | 358 (77.7) | 313 (84.1) | 372.0 (80.5) | 297.4 (82.8) | |||
| III | 35 (7.6) | 50 (13.4) | 47.6 (10.3) | 36.2 (10.1) | |||
| Smoking history | 70 (15.2) | 60 (16.1) | 0.026 | 70.5 (15.3) | 55.1 (15.4) | 0.003 | |
| Extent of surgery | 0.145 | 0.015 | |||||
| Wedge resection or metastatectomy | 37 (8.0) | 44 (11.8) | 47.3 (10.2) | 35.4 (9.9) | |||
| Segmentectomy | 80 (17.4) | 71 (19.1) | 82.3 (17.8) | 64.6 (18.0) | |||
| Lobectomy | 336 (72.9) | 250 (67.2) | 324.0 (70.1) | 252.2 (70.2) | |||
| Others | 8 (1.7) | 7 (1.9) | 8.6 (1.9) | 7.1 (2.0) | |||
| History of taking analgesics | |||||||
| Any analgesics | 40 (8.7) | 33 (8.9) | 0.007 | 42.3 (9.1) | 33.1 (9.2) | 0.002 | |
| Opioids | 11 (2.4) | 11 (3.0) | 0.035 | 14.0 (3.0) | 9.9 (2.8) | 0.017 | |
| History of taking neuropsychiatric drugs | |||||||
| Any medications | 37 (8.0) | 23 (6.2) | 0.072 | 31.5 (6.8) | 24.1 (6.7) | 0.003 | |
| Antidepressants | 29 (6.3) | 16 (4.3) | 0.089 | 24.0 (5.2) | 16.9 (4.7) | 0.022 | |
| Antianxiety drugs | 23 (5.0) | 13 (3.5) | 0.074 | 20.1 (4.3) | 13.0 (3.6) | 0.038 | |
| History of thoracic operation | |||||||
| Any side | 28 (6.1) | 26 (7.0) | 0.037 | 35.7 (7.7) | 19.6 (5.4) | 0.092 | |
| Ipsilateral side | 3 (0.7) | 11 (3.0) | 0.174 | 7.3 (1.6) | 6.4 (1.8) | 0.016 | |
| Duration of anesthesia (hr) | 2.75 (2.42–3.17) | 2.58 (2.33–3.00) | 0.166 | 2.67 (2.33–3.08) | 2.58 (2.33–3.08) | 0.015 | |
| Intraoperative opioids | |||||||
| Fentanyl | 0 (0) | 318 (85.5) | 3.432 | 0.0 (0) | 309.0 (86.0) | 3.507 | |
| Remifentanil | 461 (100) | 81 (21.8) | 2.681 | 462.1 (100.0) | 78.7 (21.9) | 2.669 | |
| Total amount of remifentanil equivalent dose (µg/kg/min) | 0.14 ± 0.04 | 0.03 ± 0.03 | 3.388 | 0.14 ± 0.04 | 0.03 ± 0.02 | 3.410 | |
| Remifentanil equivalent dose ≥ 0.2 µg/kg/min | 24 (5.2) | 0 (0) | 0.331 | 24.9 (5.4) | 0.0 (0.0) | 0.337 | |
| Intraoperative regional analgesia | 356 (77.2) | 352 (94.6) | 0.517 | 393.6 (85.2) | 315.9 (88.0) | 0.087 | |
| POD of chest tube removal | 3 (2–4) | 3 (2–5) | 0.149 | 3 (2–4) | 3 (2–5) | 0.087 | |
| Removed at POD ≥ 4 | 171 (37.1) | 149 (40.1) | 0.061 | 177.6 (38.4) | 138.9 (38.7) | 0.005 | |
| Maximum pain score at discharge day | 3 (2–3) | 3 (2–3) | 0.049 | 3 (2–3) | 3 (2–3) | 0.013 | |
The values are presented as means ± standard deviations, medians (interquartile ranges), or numbers (%).
sIPTW: stabilized inverse probability of treatment weighting, SMD: standardized mean difference, ASA: American Society of Anesthesiologists, POD: postoperative day.