Table 2.
Results of Analyses Comparing Outcomes Between Treatment Groups Subgrouped by Risk Stratificationa
| Measure | Medium-Risk Group | High-Risk Group | |||||
|---|---|---|---|---|---|---|---|
| Early Intervention Group | Usual Care Group | Mean Within-Group Difference (95% CI) | Early Intervention Group | Usual Care Group | Mean Within-Group Difference (95% CI) | Mean Interaction Effect (95% CI) | |
| Oswestry Disability Indexb | |||||||
| Baseline | 44.0 | 38.2 | 45.4 | 47.2 | |||
| 4 wk | 10.3 | 12.8 | –2.44 (–7.03 to 2.15) | 13.6 | 17.5 | –3,88 (–10.39 to 2.63) | –1.44 (–9.40 to 6.52) |
| P=.29 | P=.24 | P=.72 | |||||
| 3 mo | 6.6 | 8.5 | –2.00 (–5.85 to 1.85) | 6.1 | 12.0 | –5.87 (–11.24 to –0.50) | –3.87 (–10.50 to 2.75) |
| P=.30 | P=.03c | P=.25 | |||||
| 1 y | 6.9 | 9.5 | –2.63 (–6.95 to 1.68) | 7.1 | 9.5 | –2.36 (–8.33 to 3.61) | –0.26 (–7.11 to 7.70) |
| P=.23 | P=.43 | P=.94 | |||||
| Numeric Pain Rating Scaled | |||||||
| Baseline | 5.2 | 4.7 | 6.3 | 6.1 | |||
| 4 wk | 1.6 | 1.9 | –0.30 (–0.91 to 0.31) | 1.6 | 2.5 | –0.87 (–1.75 to –0.01) | –0.57 (–1.63 to 0.52) |
| P=.34 | P=.05c | P=.89 | |||||
| 3 mo | 1.3 | 1.6 | –0.38 (–0.97 to 0.21) | 1.3 | 2.3 | –0.98 (–1.81 to –0.14) | –0.60 (–1.61 to 0.41) |
| P=.20 | P=.02c | P=.25 | |||||
| 1 y | 1.0 | 1.4 | –0.33 (–0.91 to 0.25) | 1.0 | 1.8 | –0.74 (–1.56 to 0.08) | –0.41 (–1.41 to 0.58) |
| P=.26 | P=.07 | P=.41 | |||||
a
Results are adjusted for the baseline measure of the outcome variable.
b
Missing Oswestry Disability Index scores: 0 at baseline, 5 at 4 wk, 5 at 3 mo, and 13 at 1 y; imputed using multiple imputation procedure.
c
Significant value.
d
Missing average low back pain scores: 3 at baseline, 3 at 4 wk, 5 at 3 mo, and 13 at 1 y, imputed using multiple imputation procedure.