Comparison of in-hospital length of stay among patients with an ECI score of 1 to 5 undergoing primary 1- to 2-level lumbar fusion within the Medicare database.
| Comparison | Mean ± SD | P Value | |
| Control Group | Study Group | ||
| ECI 1 vs ECI 2 | 4.28 ± 4.36 | 6.00 ± 4.51 | <0.001 |
| ECI 1 vs ECI 3 | 4.28 ± 4.36 | 6.22 ± 4.67 | <0.001 |
| ECI 1 vs ECI 4 | 4.28 ± 4.36 | 7.35 ± 5.05 | <0.001 |
| ECI 1 vs ECI 5 | 4.28 ± 4.36 | 8.99 ± 5.67 | <0.001 |
Abbreviation: ECI, Elixhauser Comorbidity Index.