Table 4.
Interaction between treatment group and significant baseline predictor variables for back related dysfunction (Roland score).
| Treatment | Roland, 8-week* | Roland, 52-week* | |||||
| group | Predictor variable | β** | SE | P-value | β** | SE | P-value |
| Individualized acupuncture | Baseline Roland score | -0.48 | 0.12 | <.0001 | -0.23 | 0.13 | 0.07 |
| Baseline bothersomeness score | 0.30 | 0.26 | 0.25 | -0.13 | 0.28 | 0.64 | |
| Age | -0.01 | 0.05 | 0.86 | -0.02 | 0.05 | 0.64 | |
| Gender | 0.93 | 1.24 | 0.45 | -0.68 | 1.30 | 0.60 | |
| Employment, heavy lifting | 4.29 | 1.97 | 0.03 | 5.19 | 2.05 | 0.01 | |
| Employment, light/medium lifting | -0.34 | 1.62 | 0.83 | 2.18 | 1.69 | 0.20 | |
| Employment, sedentary | 1.34 | 1.67 | 0.42 | 2.73 | 1.76 | 0.12 | |
| Medication use, narcotics | 3.52 | 1.99 | 0.08 | 1.85 | 2.06 | 0.37 | |
| Medication use, other | 0.91 | 1.23 | 0.46 | 0.45 | 1.29 | 0.73 | |
| Self-efficacy | -6.17 | 2.98 | 0.04 | -3.46 | 3.46 | 0.32 | |
| Acupuncture expectation, top tertile | -2.65 | 1.34 | 0.05 | -0.98 | 1.42 | 0.49 | |
| Acupuncture expectation, could not rate | 1.43 | 1.57 | 0.36 | -0.28 | 1.64 | 0.86 | |
| Standardized acupuncture | Baseline Roland score | -0.37 | 0.13 | 0.004 | -0.24 | 0.13 | 0.07 |
| Baseline bothersomeness score | 0.47 | 0.29 | 0.10 | 0.05 | 0.31 | 0.88 | |
| Age | 0.08 | 0.05 | 0.08 | 0.07 | 0.05 | 0.15 | |
| Gender | 0.90 | 1.19 | 0.45 | 1.57 | 1.25 | 0.21 | |
| Employment, heavy lifting | 3.00 | 1.97 | 0.13 | 3.03 | 2.08 | 0.15 | |
| Employment, light/medium lifting | -0.84 | 1.62 | 0.60 | -0.67 | 1.69 | 0.69 | |
| Employment, sedentary | 1.00 | 1.63 | 0.54 | 2.47 | 1.72 | 0.15 | |
| Medication use, narcotics | 2.20 | 1.91 | 0.25 | 4.06 | 1.98 | 0.04 | |
| Medication use, other | 0.46 | 1.24 | 0.71 | 1.21 | 1.30 | 0.35 | |
| Self-efficacy | -2.91 | 3.32 | 0.38 | 1.67 | 3.49 | 0.63 | |
| Acupuncture expectation, top tertile | -1.26 | 1.31 | 0.34 | -1.90 | 1.38 | 0.17 | |
| Acupuncture expectation, could not know | 1.17 | 1.56 | 0.45 | 1.27 | 1.63 | 0.44 | |
| Simulated acupuncture | Baseline Roland score | -0.41 | 0.13 | 0.001 | -0.07 | 0.13 | 0.62 |
| Baseline bothersomeness score | 0.13 | 0.26 | 0.62 | -0.19 | 0.27 | 0.48 | |
| Age | 0.02 | 0.05 | 0.65 | 0.05 | 0.05 | 0.33 | |
| Gender | -0.48 | 1.22 | 0.69 | -0.24 | 1.28 | 0.85 | |
| Employment, heavy lifting | 2.73 | 2.04 | 0.18 | 4.45 | 2.13 | 0.04 | |
| Employment, light/medium lifting | 0.02 | 1.66 | 0.99 | -1.59 | 1.77 | 0.37 | |
| Employment, sedentary | -0.85 | 1.72 | 0.62 | 1.57 | 1.82 | 0.39 | |
| Medication use, narcotics | 4.81 | 1.96 | 0.01 | 2.71 | 2.05 | 0.19 | |
| Medication use, other | 1.17 | 1.24 | 0.35 | 1.60 | 1.32 | 0.23 | |
| Self-efficacy | 0.19 | 2.25 | 0.93 | 1.97 | 2.42 | 0.42 | |
| Acupuncture expectation, top tertile | -0.90 | 1.28 | 0.48 | -2.91 | 1.35 | 0.03 | |
| Acupuncture expectation, could not know | 0.62 | 1.59 | 0.70 | -0.17 | 1.66 | 0.92 | |
* For ease of identification, all independent variables with P < 0.5 are in boldface type
** The parameter estimates β refer to the amount of change in the outcome that is based on a one unit change in that covariate (continuous variables) or a change in category (categorical variables)