Table 1.
Summary statistics for the confounding variables
| Variable | Category | Admission (n = 1,207) | 2-year responders (n = 531) | 2-year complete cases (n = 411) | |||
|---|---|---|---|---|---|---|---|
| Frequency | % | Frequency | % | Frequency | % | ||
| Clinic | RKB | 665 | 55.1 | 290 | 54.6 | 249 | 60.6 |
| CRR | 542 | 44.9 | 241 | 45.4 | 162 | 39.4 | |
| Gender | Men | 979 | 81.1 | 423 | 79.7 | 336 | 81.7 |
| Women | 228 | 18.9 | 108 | 20.3 | 75 | 18.3 | |
| Age | NA | Mean = 41.4 | SD = 10.6 | Mean = 43.5 | SD = 10.2 | Mean = 43.3 | SD = 10.3 |
| Native language | Local | 665 | 55.1 | 370 | 69.7 | 296 | 75.0 |
| Other | 542 | 44.9 | 161 | 30.3 | 115 | 28.0 | |
| Marital status | Single | 569 | 47.1 | 231 | 43.5 | 169 | 41.1 |
| Married/partnership | 638 | 52.9 | 300 | 56.5 | 242 | 58.9 | |
| Education | ≤9 years | 594 | 49.2 | 249 | 46.9 | 203 | 50.6 |
| >9 years | 544 | 45.1 | 253 | 47.6 | 208 | 49.4 | |
| Missing values | 69 | 5.7 | 29 | 5.5 | NA | NA | |
| Time between accident and admission | <12 months | 481 | 39.8 | 219 | 41.2 | 182 | 44.3 |
| >12 months | 695 | 57.4 | 296 | 55.7 | 229 | 55.7 | |
| Missing values | 34 | 2.8 | 16 | 3.0 | NA | NA | |
| Work contract at admission | Yes | 776 | 64.3 | 368 | 69.3 | 297 | 72.3 |
| No or not known | 362 | 30.0 | 140 | 26.4 | 114 | 27.7 | |
| Missing values | 69 | 5.7 | 23 | 4.3 | NA | NA | |
| Main traumatic localization | Upper limb | 315 | 26.0 | 137 | 25.8 | 102 | 24.8 |
| Lower limb | 416 | 34.4 | 206 | 38.8 | 158 | 38.4 | |
| Neck | 207 | 17.1 | 83 | 15.6 | 72 | 17.5 | |
| Low back | 272 | 22.5 | 105 | 19.8 | 79 | 19.2 | |