Table 3.
Responsiveness of change in work functioning impairment scale (WFun) for changes in pain numeric rating scale (NRS) and productivity-NRS.
| Change in measure | Cumulative total number across the 4 waves | Mean change in WFun score | SD | Multilevel analyses* | ||
|---|---|---|---|---|---|---|
| Coefficient | SE | p | ||||
| SD, standard deviation; SE, standard error. Positive change scores on pain-NRS and WFun indicate worsened pain and reduced ability to work due to pain, respectively. Positive change scores on productivity-NRS indicate improved ability to work. * Multilevel analyses were conducted such that repeated measurements were nested in individuals. | ||||||
| Pain-NRS | ||||||
| –9 to –4 | 78 | –2.6 | 8.0 | –2.4 | 0.7 | 0.001 |
| –3 to –2 | 280 | –1.1 | 6.7 | –1.0 | 0.4 | 0.018 |
| –1 to 1 | 1311 | –0.2 | 6.0 | Reference | ||
| 2 to 3 | 270 | 1.1 | 6.6 | 1.2 | 0.4 | 0.003 |
| 4 to 7 | 56 | 2.2 | 5.2 | 2.4 | 0.9 | 0.005 |
| Productivity-NRS | ||||||
| 5 to 10 | 30 | –2.2 | 9.3 | –2.3 | 1.2 | 0.044 |
| 1 to 4 | 659 | –1.3 | 6.3 | –1.4 | 0.3 | <0.001 |
| –1 to 0 | 1011 | 0.1 | 5.8 | Reference | ||
| –4 to –2 | 265 | 1.4 | 6.9 | 1.3 | 0.4 | 0.003 |
| –10 to –5 | 30 | 2.8 | 8.7 | 2.7 | 1.2 | 0.024 |