Table 1 Comparison of preoperative basic characteristics between the two groups before and after 1:4 PSM
| Â | Before PSM | After 1:4 PSM | ||||||
|---|---|---|---|---|---|---|---|---|
Characteristic | Obese (n = 30) | Control (n = 144) | p value | SMD | Obese (n = 28) | Control (n = 80) | p value | SMD |
Sex, n (%) |  |  | 0.074 | 0.458 |  |  | 0.922 | −0.034 |
 Male | 26 (86.7) | 102 (70.8) |  |  | 24 (85.7) | 66 (82.5) |  |  |
 Female | 4 (13.3) | 42 (29.2) |  |  | 4 (14.3) | 14 (17.5) |  |  |
Age (years), mean ± SD | 18.27 ± 2.26 | 18.78 ± 2.37 | 0.275 | −0.229 | 18.07 ± 2.21 | 18.16 ± 2.61 | 0.869 | −0.058 |
Duration of symptoms(months), M (IQR) | 6 (3.5–12.0) | 6 (3.0–12.0) | 0.951 | 0.028 | 6 (2.5–10.0) | 6 (3.0–12.0) | 0.916 | 0.021 |
History of trauma, n (%) |  |  | 0.464 | −0.157 |  |  | 0.452 | −0.095 |
 Yes | 6 (20.0) | 38 (26.4) |  |  | 6 (21.4) | 23 (28.7) |  |  |
 No | 24 (80.0) | 106 (73.6) |  |  | 22 (78.6) | 57 (71.3) |  |  |
Herniated segment, n (%) |  |  | 0.004* | −0.581 |  |  | 0.362 | −0.051 |
 L4-L5 | 23 (76.7) | 66 (45.8) |  |  | 21 (75.0) | 50 (62.5) |  |  |
 L5-S1 | 6 (20.0) | 74 (51.4) |  |  | 6 (21.4) | 28 (35.0) |  |  |
 Other level | 1 (3.3) | 4 (2.9) |  |  | 1 (3.6) | 2 (2.5) |  |  |
Herniated type, n (%) |  |  | 0.012* | −0.521 |  |  | 0.280 | −0.012 |
 Lateral | 20 (66.7) | 60 (41.7) |  |  | 10 (35.7) | 38 (47.5) |  |  |
 Central | 10 (33.3) | 84 (58.3) |  |  | 18 (64.3) | 42 (52.5) |  |  |
Preoperative VAS, mean ± SD | 6.20 ± 1.35 | 6.72 ± 1.06 | 0.023* | −0.382 | 6.29 ± 1.36 | 6.49 ± 1.14 | 0.444 | 0.051 |
Preoperative ODI, mean ± SD | 58.47 ± 10.27 | 61.92 ± 9.22 | 0.069 | −0.366 | 58.36 ± 10.64 | 60.36 ± 9.56 | 0.356 | −0.005 |