Receiver operating characteristic curve analysis of 2- and 3-level posterolateral lumbar fusion with patient-reported outcomes.
| Outcomes | Estimated Blood Loss, mL | Area Under the Curve (95% CI) | P Value |
| 2-Level Fusion (N = 557) | |||
| Length of stay POD2 | 375 | 0.64 (0.58–0.7) | <0.001 |
| Complication (30 d) | 637.5 | 0.5 (0.38–0.61) | <0.001 |
| MCID ODI | 287.5 | 0.54 (0.48–0.6) | <0.001 |
| MCID NRS back | 975 | 0.53 (0.46–0.59) | <0.001 |
| MCID NRS leg | 975 | 0.51 (0.44–0.57) | <0.001 |
| 3-Level Fusion (N = 287) | |||
| Length of stay POD2 | 675 | 0.63 (0.54–0.73) | 0.012 |
| Complication (30 d) | 538 | 0.63 (0.51–0.76) | <0.001 |
| MCID ODI | 675 | 0.52 (0.44–0.6) | <0.001 |
| MCID NRS back | 512.5 | 0.57 (0.49–0.65) | <0.001 |
| MCID NRS leg | 375 | 0.46 (0.37–0.56) | <0.001 |
Abbreviations: MCID, minimal clinically important difference; NRS, Numerical Rating Scale; ODI, Oswestry Disability Index; POD2, postoperative day 2.