Table 4
The explained variance (Adjusted R2) and associations between EQ-5D as outcome and predictors (entered in 5 blocks) explored by linear regression analysis (n = 941)
| Blocks of predictors | Block 1 | Block 1–2 | Block 1–3 | Block 1–4 (Final model) | Block 1-5c | |
|---|---|---|---|---|---|---|
| Adjusted R2 | Adjusted R2 | Adjusted R2 | Adjusted R2 | Adjusted R2 | ||
| 0.18 | 0.21 | 0.21 | 0.21 | 0.42 | ||
| Coefficients (95% CI) | Coefficients (95% CI) | Coefficients (95% CI) | Coefficients (95% CI) | Coefficients (95% CI) | ||
| Patient previous course of pain (n, %) | ||||||
| Single episode | Block 1 | Ref | Ref | Ref | Ref | Ref |
| Episodic pain | -1.69 (-4.24 to 0.86) | -0.96 (-3.47 to 1.55) | -0.86 (-3.36 to 1.64) | -0.85 (-3.36 to 1.67) | 1.05 (-3.23 to 1.12) | |
| Mild pain/recovering | -1.99 (-5.18 to 1.20) | -1.44 (-4.58 to 1.71) | -1.37 (-4.51 to 1.77) | -1.38 (-4.53 to 1.76) | -1.92 (-4.64 to 0.81) | |
| Fluctuating pain | -6.39 (-8.97 to -3.80) | -4.83 (-7.42 to -2.25) | -4.69 (-7.28 to -2.11) | -4.72 (-7.31 to -2.13) | -3.06 (-5.30 to -0.81) | |
| Moderate/severe pain | -11.66 (-16.52 to -6.80) | -9.67 (-14.48 to -4.87) | -9.54 (-14.35 to -4.74) | -9.57 (-14.38 to -4.76) | -2.42 (-6.65 to 1.81) | |
| Neither/ Unsure | -4.90 (-9.61 to -0.18) | -5.27 (-9.91 to -0.62) | -5.04 (-9.67 to -0.40) | -5.05 (-9.68 to -0.41) | -4.64 (-8.77 to -0.51) | |
| Patient expected course of pain (n, %) | ||||||
| Single episode | Block 2 | Ref | Ref | Ref | Ref | Ref |
| Episodic pain | -3.09 (-5.02 to -1.17) | -2.68 (-4.57 to -0.79) | -2.69 (-4.57 to -0.80) | -2.70 (-4.60 to -0.80) | -2.07 (-3.70 to -0.43) | |
| Mild pain/recovering | -3.77 (-6.35 to -1.18) | -3.14 (-5.68, -0.61) | -3.15 (-5.68 to -0.61) | -3.15 (-5.70 to -0.60) | -2.40 (-4.60 to -0.19) | |
| Fluctuating pain | -6.25 (-8.55 to -3.96) | -5.45 (-7.71 to -3.19) | -5.39 (-7.66 to -3.13) | -5.38 (-7.70 to -3.06) | -4.12 (-6.12 to -2.11) | |
| Moderate/severe pain | -25.32 (-34.65 to -16.00) | -24.47 (-33.62 to -15.32) | -25.36 (-34.50 to -16.22) | -25.39 (-34.58 to -16.21) | -21.59 (-29.51 to -13.66) | |
| Neither/ Unsure | -2.67 (-5.10 to -0.23) | -1.91 (-4.30 to 0.48) | -1.98 (-4.37 to 0.40) | -1.98 (-4.38 to 0.42) | -1.50 (-3.57 to 0.58) | |
| Radiating pain to shoulder and/or elbow (Ref.: yes) | 1.23 (-0.37 to 2.84) | 1.15 (-0.46 to 2.77) | 1.16 (-0.45 to 2.78) | 1.14 (-0.27 to 2.55) | ||
| Number of MSK pain sites | -1.09 (-1.42 to -0.76) | -0.91 (-1.44 to -0.37) | -0.91 (-1.44 to -0.37) | -0.23 (-0.70 to 0.24) | ||
| Education level | ||||||
| Low | Block 3 | Ref | Ref | Ref | ||
| Medium | 3.56 (0.47 to 6.25) | 3.37 (0.48 to 6.27) | 1.50 (-1.01 to 4.00) | |||
| High | 2.21 (-0.66 to 5.07) | 2.21 (-0.65 to 5.08) | 1.04 (-1.43 to 3.51) | |||
| Physical leisure activity (Ref.: yes) | 2.06 (-1.08 to 5.20) | 2.07 (-1.07 to 5.22) | 2.02 (-0.69 to 4.73) | |||
| Physical leisure activity#Number of MSK pain-sites | -0.25 (-0.86 to 0.35) | -0.26 (-0.86 to 0.35) | -0.35 (-0.88 to 0.17) | |||
| Consultation-type | ||||||
| First-time consultation | Block 4 | Ref | Ref | |||
| Follow-up consultation | 0.56 (-1.34 to 2.46) | -0.85 (-2.50 to 0.80) | ||||
| Maintenance consultation | 0.36 (-1.40 to 2.13) | -1.88 (-3.43 to -0.34) | ||||
| Baseline EQ-5D | Block 5c | 0.41 (0.37 to 0.46) | ||||
Note: The 95% C.I not including 0 are marked in bold, The EQ5D index-scale is transformed to a 0–100 scale for both baseline and outcome