Table 2.
Regression analysis of linear and quadratic trends for time series (T0, T1, and T2) of VAS, QL2, GIF, and GSI scores.
| Scales for Rehabilitation Assessment | Trend | Estimated Coefficient | Std. Error | t Value | Pr(>|t|) | Cohen’s d | Effect Size Level |
|---|---|---|---|---|---|---|---|
| VAS | lin. | −1.641 | 0.222 | −7.395 | <0.001 | 2.368 | high |
| quadr. | −1.487 | 0.187 | −7.959 | <0.001 | 2.549 | high | |
| QL2 | lin. | 30.718 | 3.757 | 8.176 | <0.001 | 2.618 | high |
| quadr. | −0.821 | 4.193 | −0.196 | 0.846 | |||
| GIF | lin. | 24.230 | 3.530 | 6.865 | <0.001 | 2.199 | high |
| quadr. | 3.974 | 3.405 | 1.167 | 0.250 | |||
| GSI | lin. | −16.282 | 2.634 | −6.182 | <0.001 | 1.980 | high |
| quadr. | −4.179 | 2.434 | −1.717 | 0.094 |
Significant p values are in bold. VAS: Visual Analog Scale of pain; QL2: Quality-of-Life scale (revised); GIF: Global Index of Functioning; GSI: Global Symptom Index. Lin.: linear trend; quadr.: quadratic trend.