Table 1 Characteristics of patients in the total, training, and validation cohorts
Characteristics | Total cohort (n = 344) | Training cohort (n = 240) | Validation cohort (n = 104) | P value |
|---|---|---|---|---|
Age, year | 55.0 (40.8–66.0) | 54.0 (39.0–65.0) | 59.5 (45.0–66.0) | 0.269 |
Gender | 0.490 | |||
Female | 159 (46.2) | 108 (40.8) | 51 (49.0) | Â |
Male | 185 (53.8) | 132(59.1) | 53 (50.1) | Â |
Comorbidities | 0.982 | |||
No | 132 (38.4) | 92 (38.3) | 40 (38.5) | Â |
Yes | 212 (61.6) | 148 (61.7) | 64 (61.5) | Â |
BMI | 24.9 (22.0–27.8) | 24.7 (22.3–28.1) | 25.0 (21.7–27.6) | 0.554 |
Surgical site | 0.458 | |||
Joint | 96 (27.91) | 64 (26.67) | 32 (30.77) | Â |
Spine | 77 (22.38) | 58 (24.17) | 19 (18.27) | Â |
Limbs | 171 (49.71) | 118 (49.17) | 53 (50.96) | Â |
ASA class | 0.214 | |||
1 | 77 (22.38) | 56 (23.33) | 21 (20.19) | Â |
2 | 235 (68.31) | 166 (69.17) | 69 (66.35) | Â |
3 | 32 (9.3) | 18 (7.5) | 14 (13.46) | Â |
NNIS class | 0.519 | |||
0 | 291 (84.59) | 205 (85.42) | 86 (82.69) | Â |
1 | 53 (15.41) | 35 (14.58) | 18 (17.31) | Â |
Postoperative drainage | 0.381 | |||
No | 232 (67.44) | 158 (65.83) | 74 (71.15) | Â |
Yes | 112 (32.56) | 82 (34.17) | 30 (28.85) | Â |
Implants | 0.062 | |||
No | 90 (26.16) | 70 (29.17) | 20 (19.23) | Â |
Yes | 254 (73.84) | 170 (70.83) | 84 (80.77) | Â |
Operation time | 67.4 (45.8–106.1) | 67.6 (45.0–109.0) | 67.2 (48.4–87.3) | 0.791 |
Length of hospital stay | 3.0 (2.0–5.0) | 3.0 (2.0–5.0) | 3.0 (2.0–5.0) | 0.736 |
RBC, 1012 /L | 4.4 (4.0–4.8) | 4.5 (4.1–4.8) | 4.4 (3.9–4.6) | 0.122 |
WBC, 109 /L | 6.6 (5.5–7.9) | 6.4 (5.3–7.8) | 6.9 (5.9–8.0) | 0.124 |
Platelet, 109 /L | 237.0 (196.0–282.5) | 234.0 (196.0–282.5) | 240.5 (199.0–282.8) | 0.677 |
Haemoglobin, g/L | 133.0 (120.0–144.2) | 133.0 (121.0–146.0) | 131.0 (117.5–142.2) | 0.076 |
AST, U/L | 20.0 (15.0–25.0) | 19.0 (15.0–25.0) | 20.0 (16.0–24.0) | 0.361 |
ALT, U/L | 18.0 (13.0–27.0) | 18.0 (13.0–27.0) | 18.5 (13.0–26.2) | 0.584 |
Total bilirubin, μmol/L | 15.3 (11.8–19.1) | 15.3 (11.8–19.2) | 15.3 (11.3–18.9) | 0.699 |
Direct bilirubin, μmol/L | 3.6 (2.8–4.8) | 3.6 (2.8–4.9) | 3.6 (2.9–4.8) | 0.714 |
GGT, IU/L | 20.0 (17.0–24.0) | 20.0 (17.0–23.2) | 20.0 (17.8–24.2) | 0.947 |
Albumin, g/L | 40.7 (39.0–42.8) | 40.7 (39.1–42.8) | 40.7 (38.1–42.1) | 0.078 |
Creatinine, μmol/L | 58.5 (51.9–68.1) | 58.5 (51.9–68.3) | 58.3 (52.1–67.3) | 0.887 |
Prothrombin time, s | 12.1 (11.3–12.7) | 12.1 (11.3–12.8) | 12.0 (11.3–12.5) | 0.206 |
D-Dimer, μg/mL | 0.5 (0.2–1.1) | 0.5 (0.2–1.1) | 0.5 (0.2–1.5) | 0.464 |
SSI | 0.999 | |||
No | 305 (88.66) | 213 (88.75) | 92 (88.46) | Â |
Yes | 39 (11.34) | 27 (11.25) | 12 (11.54) | Â |