Bivariate analysis achievement for SF-12 PCS.
| Characteristic | Failed MCID (%) | RR | 95% CI | P valuea |
| Overall | 22.2% | – | – | – |
| Age | ||||
| 18–50 y | 58.9% | Reference | ||
| <50 y | 41.1% | 1.3 | (1.1–1.7) | 0.035 |
| Gender | ||||
| Male | 32.2% | 0.9 | (0.7–1.2) | 0.451 |
| Female | 67.8% | Reference | ||
| BMI | ||||
| <30 kg/m2 | 57.1% | Reference | ||
| ≥30 kg/m2 | 42.9% | 1.1 | (0.9–1.5) | 0.306 |
| Smoking status | ||||
| Nonsmoker | 83.3% | Reference | ||
| Smoker | 16.7% | 0.9 | (0.7–1.4) | 0.967 |
| Diabetes | ||||
| Nondiabetic | 94.4% | Reference | ||
| Diabetic | 5.6% | 0.9 | (0.5–1.7) | 0.877 |
| Ageless CCI | ||||
| <1 | 53.2% | Reference | ||
| ≥1 | 46.8% | 1.3 | (0.9–1.6) | 0.085 |
| ASA score | ||||
| <2 | 34.0% | Reference | ||
| ≥2 | 66.0% | 1.0 | (0.7–1.4) | 0.888 |
| Insurance | ||||
| Non-WC | 70.6% | Reference | ||
| WC | 29.4% | 1.1 | (0.8–1.4) | 0.663 |
| Operative length | ||||
| <50 min | 74.4% | Reference | ||
| ≥50 min | 25.6% | 0.7 | (0.5–0.9) | 0.025 |
| EBL | ||||
| <50 mL | 93.0% | Reference | ||
| ≥50 mL | 7.0% | 0.9 | (0.6–1.3) | 0.720 |
| Operative levels | ||||
| Single | 80.0% | Reference | ||
| Multilevel | 20.0% | 1.1 | (0.8–1.5) | 0.486 |
| Operative technique | ||||
| Laminectomy only | 21.3% | 1.2 | (0.9–1.5) | 0.076 |
| Discectomy only | - | - | - | - |
| Laminectomy + discectomy | 77.3% | 0.8 | (0.7–1.0) | 0.096 |
| Spinal pathologies | ||||
| HNP | 75.0% | 0.7 | (0.6–1.0) | 0.050 |
| Central stenosis | 76.1% | 2.0 | (1.5–2.8) | 0.001 |
| Foraminal stenosis | 50.0% | 1.9 | (1.5–2.5) | 0.001 |
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; RR, relative risk; SF-12, 12 item short form; WC, workers’ compensation.