Table 1.
Clinical Comparison Between Patients with and without Basal Infusion of Intravenous Patient-Controlled Analgesia Before and After Propensity Score Matching
| Before Matching | After Matching | |||||||
|---|---|---|---|---|---|---|---|---|
| Basal Group (n=560) | No Basal Group (n=757) | P-value | Standardized Difference | Basal Group (n=539) | No Basal Group (n=539) | P-value | Standardized Difference | |
| Female | 243 (43.4) | 316 (41.7) | 0.588 | 0.033 | 233 (43.2) | 231 (42.9) | 0.951 | 0.007 |
| Age, year | 60 (51–67) | 63 (53–72) | < 0.001 | −0.255 | 60 (51–67) | 61 (51–70) | 0.283 | −0.048 |
| Height, cm | 163.8 (157.2–169.6) | 163.3 (157.2–168.9) | 0.310 | 0.051 | 163.8 (157.2–169.4) | 163.5 (157.1–169.0) | 0.535 | 0.035 |
| Weight, kg | 63.4 (56.2–71.2) | 63.2 (55.8–70.9) | 0.459 | 0.070 | 63.1 (56.0–70.8) | 64.0 (55.8–71.3) | 0.831 | 0.021 |
| BMI, kg/m2 | 23.8 (21.5–26.0) | 23.9 (21.8–25.9) | 0.971 | 0.046 | 23.7 (21.5–25.9) | 24.1 (21.7–26.1) | 0.483 | −0.002 |
| ASA physical status, I/II/III/IV | 115 (20.5)/364 (65.0)/81 (14.5)/0 | 128 (16.9)/532 (70.3)/96 (12.7)/1 (0.1) | 0.129 | 0.037 | 108 (20.0)/352 (65.3)/79 (14.7)/0 | 100 (18.6)/374 (69.4)/64 (11.9)/1 (0.2) | 0.277 | 0.016 |
| Current smoker | 85 (15.2) | 106 (14.0) | 0.549 | 0.033 | 77 (14.3) | 80 (14.8) | 0.796 | 0.016 |
| Preoperative analgesic use | 25 (4.5) | 48 (6.3) | 0.177 | 0.091 | 25 (4.6) | 25 (4.6) | > 0.999 | < 0.001 |
| Preoperative strong opioid use | 4 (0.7) | 8 (1.1) | 0.724 | 0.037 | 4 (0.7) | 4 (0.7) | > 0.999 | 0 |
| Preoperative antipsychotics use | 12 (2.1) | 21 (2.8) | 0.585 | 0.041 | 12 (2.2) | 12 (2.2) | > 0.999 | 0 |
| Type of surgery | 0.007 | −0.191 | 0.484 | 0.006 | ||||
| General surgery | 366 (65.4) | 446 (58.9) | 347 (64.4) | 358 (66.4) | ||||
| Thoracic surgery | 61 (10.9) | 72 (9.5) | 60 (11.1) | 46 (8.5) | ||||
| Urologic surgery | 105 (18.8) | 171 (22.6) | 104 (19.3) | 102 (18.9) | ||||
| Plastic surgery | 28 (5.0) | 68 (9.0) | 28 (5.2) | 33 (6.1) | ||||
| SORT classification, II/III/IV | 31(5.5)/140 (25.0)/389 (69.5) | 51 (6.7)/179 (23.6)/527 (69.6) | 0.609 | 0.018 | 31 (5.8)/134 (24.9)/374 (69.4) | 36 (6.7)/119 (22.1)/384 (71.2) | 0.498 | −0.016 |
| Type of anesthesia | 0.337 | 0.053 | 0.682 | 0.025 | ||||
| Inhalation agent | 404 (72.1) | 564 (74.5) | 388 (72.0) | 394 (73.1) | ||||
| TIVA | 156 (27.9) | 193 (25.5) | 151 (28.0) | 145 (26.9) | ||||
| Surgical time, min | 135 (91–199) | 125 (85–191) | 0.105 | 0.063 | 135.0 (91.0–198.0) | 130.0 (83.0–199.0) | 0.525 | 0.022 |
| Continuous wound-infiltration analgesia use | 12 (2.1) | 28 (3.7) | 0.143 | −0.107 | 11 (2.0) | 14 (2.6) | 0.686 | −0.038 |
Note: The values are presented as the median (interquartile range) or number (%).
Abbreviations: ASA, American society of anesthesiologists; SORT, Surgical Outcome Risk Tool; TIVA, total intravenous anesthesia.