Baseline Characteristics
| Characteristic | CC * | Spacer† | DS‡ | Comparison p-value§ | ||
|---|---|---|---|---|---|---|
| CC v Spacer | CC v DS | Spacer v DS | ||||
| Number of patients | 100 | 189 | 129 | NA | NA | NA |
| Age, mean (SD) | 58 (12) | 66 (9) | 64 (11) | <0.05 | <0.05 | NS |
| Male, % | 40 | 58 | 59 | <0.05 | <0.05 | NS |
| ODI, mean (SD) | 57 (19) | 39 (13) | 47 (14) | <0.05 | <0.05 | <0.05 |
| SF-12 PCS, mean (SD) | 31.4 (8.1) | 29.2 (8.4) | 26.7 (9.4) | <0.05 | <0.05 | <0.05 |
| SF-12 MCS, mean (SD) | 49.2 (12.1) | 49.9 (13.1) | 48.2 (11.2) | NS | NS | NS |
| 1 Level treated, % | NA | 52 | 45 | NS | NS | NS |
| 2 Levels treated, % | NA | 48 | 55 | |||
SD: Standard deviation.
↵* CC: Conservative Care, from Parker et al. 2014. Results from spondylolisthesis and stenosis patients were combined.
↵† Spacer: from ISISS trial, Superion patients.
↵‡ DS: Decompressive Surgery without fusion, from institutional registry.
↵§ For continuous variables, a two sample Z-test was used for the pairwise comparisons. For categorical variables, Fisher's exact test was used. A p-value of 0.05 was considered statistically significant. No corrections for multiplicity were applied.