Bivariate analysis achievement for ODI.
| Characteristic | Failed MCID (%) | RR | 95% CI | P valuea |
| Overall | 26.8% | – | – | – |
| Age | ||||
| 18–50 y | 53.7% | Reference | ||
| <50 y | 46.3% | 1.6 | (1.3–2.0) | 0.001 |
| Gender | ||||
| Male | 26.7% | 1.2 | (0.9–1.5) | 0.231 |
| Female | 73.3% | Reference | ||
| BMI, kg/m2 | ||||
| <30 | 60.3% | Reference | ||
| ≥30 | 39.7% | 1.0 | (0.7–1.3) | 0.974 |
| Smoking status | ||||
| Nonsmoker | 82.5% | Reference | ||
| Smoker | 17.5% | 1.1 | (0.8–1.4) | 0.731 |
| Diabetes | ||||
| Nondiabetic | 93.5% | Reference | ||
| Diabetic | 6.5 | 1.1 | (0.7–1.8) | 0.622 |
| Ageless CCI | ||||
| <1 | 46.9% | Reference | ||
| ≥1 | 53.1% | 1.6 | (1.3–2.1) | 0.001 |
| ASA score | ||||
| <2 | 30.8% | Reference | ||
| ≥2 | 69.2% | 1.2 | (0.9–1.6) | 0.241 |
| Insurance | ||||
| Non-WC | 69.1% | Reference | ||
| WC | 30.8% | 1.0 | (0.8–1.3) | 0.725 |
| Operative length | ||||
| <50 min | 68.7% | Reference | ||
| ≥50 min | 31.3% | 0.9 | (0.8–1.0) | 0.158 |
| EBL | ||||
| <50 mL | 91.6% | Reference | ||
| ≥50 mL | 8.4% | 1.1 | (0.7–1.6) | 0.472 |
| Operative levels | ||||
| Single | 72.8% | Reference | ||
| Multilevel | 27.2% | 1.7 | (1.3–2.1) | 0.001 |
| Operative technique | ||||
| Laminectomy only | 27.4% | 1.5 | (1.1–1.9) | 0.001 |
| Discectomy only | - | - | - | - |
| Laminectomy + discectomy | 71.3% | 1.0 | (0.8–1.3) | 0.796 |
| Spinal pathologies | ||||
| HNP | 70.1% | 0.6 | (0.5–0.9) | 0.003 |
| Central stenosis | 73.7% | 1.8 | (1.4–2.3) | 0.001 |
| Foraminal stenosis | 41.9% | 1.4 | (1.1–1.7) | 0.003 |
Boldface indicates statistical significance.
aP value calculated using Poisson regression.
ASA, American Society of Anesthesiologists; BMI, body mass index; CCI, Charlson Comorbidity Index; EBL, estimated blood loss; HNP, herniated nucleus pulposus; ODI, Oswestry Disability Index; RR, relative risk; WC, workers’ compensation.