NDI Change from preoperative to 12 months: mean (SD).
| NDI | Non Depressed Non Smoker N=91 | Non Depressed Smoker N=61 | Depressed Non Smoker N=55 | Depressed Smoker N=65 | P* |
|---|---|---|---|---|---|
| Pre-Op | 47.8 (15.6) | 49.5 (14.4) | 60.8 (16.0) | 63.3 (14.3) | <.001 |
| 12-month | 22.8 (18.8) | 22.7 (17.6) | 35.3 (21.5) | 28.8 (20.3) | .001 |
| Change | 25.0 (20.6) | 26.8 (19.1) | 25.5 (19.9) | 34.5 (23.1) | .029 |
NDI, Neck Disability Index.