TABLE 1.
Baseline Demographic and Health-related Quality of Life Scores for Both the derivation and validation cohort of Patients
| Variable | Derivation Cohort | Validation Cohort | P |
|---|---|---|---|
| N | 200 | 108 | |
| Age, y, mean ± standard deviation | 56.6 ± 18.8 | 59.9 ± 17.3 | 0.15 |
| Female (no.of patients) | 89 (46%) | 51 (47%) | 0.65 |
| Body mass index, kg/m2, mean ± standard deviation | 26.9 ± 5.5 | 27.1 ± 4.7 | 0.73 |
| Diagnosis | |||
| Spondylolisthesis (no. of patients) | 55 (28%) | 27 (25%) | 0.64 |
| Disc herniation (no. of patients) | 65 (33%) | 32 (30%) | 0.60 |
| Central stenosis (no. of patients) | 96 (43%) | 51 (47%) | 0.90 |
| Foraminal stenosis (no. of patients) | 62 (31%) | 41 (37%) | 0.22 |
| Degenerative disc disease (no. of patients) | 78 (39%) | 44 (41%) | 0.77 |
| PreOp HRQOL (mean ± standard deviation) | |||
| VAS leg | 4.9 ± 3.3 | 5.5 ± 3.3 | 0.16 |
| VAS back | 5.1 ± 3.9 | 5.2 ± 3.2 | 0.96 |
| Sf-12 MHS | 47.1 ± 13.5 | 50.0 ± 41.9 | 0.39 |
| SF-12 PHS | 32.3 ± 9.3 | 31.4 ± 9.6 | 0.44 |
| ODI | 41.6 ± 19.3 | 40.2 ± 19.4 | 0.58 |
| PROMIS | 30.0 ± 14.7 | 29.1 ± 15.3 | 0.63 |
| Muscle measurements | |||
| Total cross-sectional area of paralumbar muscle, mm2, mean ± standard deviation) | 3852.8 ± 1073.4 | 3851.6 ± 1248.3 | 0.99 |
| Lumbar indentation value, mm, mean ± standard deviation) | 14.1 ± 6.0 | 14.2 ± 6.3 | 0.88 |
| Goutallier classification | |||
| 1 (no. of patients) | 31 (15%) | 23 (21%) | 0.20 |
| 2 (no. of patients) | 112 (56%) | 48 (44%) | 0.06 |
| 3 (no. of patients) | 34 (16%) | 26 (24%) | 0.13 |
| 4 (no. of patients) | 23 (12%) | 11 (10%) | 0.72 |
ODI indicates Oswestry Disability Index; PROMIS, Patient-reported Outcomes Measurement Information System; SF-12 PHS, short-form 12 physical health score; SF-12 MHS, short-form 12 mental health score; VAS, Visual Analog Scale.