Table 6 Subgroup analyses: differences in treatment effects between subgroups (statistical test of interaction)
Primary outcomes | Subgroups | |||
|---|---|---|---|---|
Low risk (0–3) IG versus CG | Medium/High risk (> 3) IG versus CG | |||
Back pain severity (CPGQ) | characteristic back pain intensity (0–100) | Mean Difference (SE) between IG / CG | - 1.0 (2.17) | + 7.4 (2.69) |
Δ of treatment effect in the both subgroups (SE) | 8.4 (3.46) | |||
z-score/ p | 2.428/ 0.015 | |||
disability points (0–6) | mean difference (SE) between IG / CG | 0.05 (0.22) | 0.68 (0.28) | |
Δ of treatment effect in the both subgroups (SE) | 0.63 (0.36) | |||
z-score/ p | 1.750 / 0.080 | |||
Health-related quality of life (SF-12) | physical component (0–100) | mean difference (SE) between IG / CG | 0.9 (1.10) | 3.9 (1.34) |
Δ of treatment effect in the both subgroups (SE) | 3.0 (1.73) | |||
z-score/ p | 1.734 / 0.083 | |||
mental component (0–100) | mean difference (SE) between IG / CG | - 2.1 (1.38) | 2.7 (1.60) | |
Δ of treatment effect in the both subgroups (SE) | 4.8 (2.11) | |||
z-score/ p | 2.275/ 0.023 | |||