Table 4.
Unadjusted and Adjusted Associations of Patient or Surgical Characteristics and Achievement of the Minimal Clinically Important Difference for Back Pain Improvement Among 84 Patients Who Underwent Lumbar Fusion Surgery for Back Pain and Degenerative Disc Disease.
| Variable | Unadjusted univariable associations | Adjusted multiple binomial regression Model fit: R2 = 0.24 |
||||
|---|---|---|---|---|---|---|
| OR | 95% CI | p-value | OR | 95% CI | p-value | |
| Age | 0.98 | 0.94-1.02 | 0.39 | - | - | - |
| Sex | 1.33 | 0.48-3.74 | 0.59 | - | - | - |
| Body Mass Index | 1.02 | 0.92-1.31 | 0.72 | - | - | - |
| Living status | 0.38 | 0.10-1.53 | 0.17 | 0.38 | 0.83-1.78 | 0.22 |
| Education | 0.69 | 0.23-2.05 | 0.51 | - | - | - |
| Smoking status | 1.46 | 0.37-5.75 | 0.59 | - | - | - |
| Claims | 0.56 | 0.20 –1.58 | 0.27 | - | - | - |
| Comorbidities | 0.84 | 0.64-1.11 | 0.22 | - | - | - |
| Daily opiate use | 1.30 | 0.45-3.72 | 0.63 | - | - | - |
| Duration of symptoms | 0.90 | 0.79-1.03 | 0.14 | 0.83 | 0.70-0.99 | 0.37 |
| Anterior vs posterior | 0.55 | 0.15-2.05 | 0.37 | - | - | - |
| Direct decompression | 0.76 | 0.26-2.22 | 0.62 | - | - | - |
| Number of levels | 0.76 | 0.46-1.25 | 0.28 | - | - | - |
| Interbody cage | 1.00 | 0.51-1.93 | 0.99 | - | - | - |
| PHQ9 score | 1.00 | 0.91-1.09 | 0.94 | - | - | - |
| NPRS back pain* | 1.33 | 1.07-1.96 | 0.02 | 1.72 | 1.17-2.52 | <0.01 |
| ODI score* | 0.97 | 0.93-1.00 | 0.08 | - | - | - |
| Study site | 0.98 | 0.91-1.06 | 0.66 | - | - | - |
OR = odds ratio; CI = confidence interval; PHQ9 = Patient Health Questionnaire 9; NPRS = Numerical Pain Rating Scale; ODI = Oswestry Disability Index.
*Pre-operative ODI score was omitted from the final multiple binomial regression model because it was highly colinear with pre-operative NPRS back pain score (Pearson Correlation Coefficient 0.41, p < 0.001).