From: Variable selection under multiple imputation using the bootstrap in a prognostic study
 | Trial 1 (n = 134) | Trial 2 (n = 195) | Trial 3 (n = 299) | Missing (%) | Value |
---|---|---|---|---|---|
Age (mean years ± sd) |
|
|
| 0 | 40.6 (9.5) |
Gender (male, %) |
|
|
| 0 | 71.0 |
Education (%) |
|
|
| 26.1 | 73.9 |
Smoking (%) |
|
|
| 7.5 | 43.8 |
Self-predicted certainty at 6 months (%) |
|
|
| 24.4 | 75.6 |
Physical activity (mean ± sd) |  |
|
| 44.6 | 8.8 (1.0) |
Bodyweight (kg) (mean ± sd) |
|
|
| 3.3 | 81.1 (15.8) |
Height (cm) (mean ± sd) |
|
|
| 3.3 | 176.6 (9.4) |
Quality of life (mean ± sd) |
|
|
| 2.7 | 0.5 (0.07) |
Years working in current job (median, IQR) | Â |
|
| 24.2 | 35.0 (28) |
Full work absence (vs partial) (%) |
|
|
| 0.8 | 67.0 |
Job satisfaction (%) | Â |
|
| 2.9 | 97.1 |
Job Content Questionnaire: | Â | Â | Â | Â | Â |
   Job control (mean ± sd) |  |
|
| 25.6 | 56.2 (9.2) |
   Job demands (mean ± sd) |  |
|
| 24.7 | 33.1 (4.8) |
   Social support (mean ± sd) |  |
|
| 24.8 | 22.5 (4.1) |
Daily exposed to: | Â | Â | Â | Â | Â |
   Vibration tools (%) |  |
|
| 27.1 | 5.7 |
   Lifting >25 kg (%) |  |
|
| 24.2 | 15.3 |
   Bending and twisting of the trunk (%) |  |
|
| 24.2 | 20.2 |
   Whole body vibration (%) |  |
|
| 26.4 | 7.8 |
   Sitting (%) |  |
|
| 24.7 | 14.2 |
   Working with hands under knee level (%) |  |
|
| 25.0 | 6.6 |
   Stooping (%) |  |
|
| 25.2 | 19.6 |
Duration of complaints (weeks) prior to randomization; (median, IQR) |
|
|
| 33.3 | 5.8 (13.3) |
Pain radiation in 1 or both legs (%) |
|
|
| 2.1 | 33.8 |
Functional status (RDQ) (mean ± sd) |
|
|
| 5.1 | 11.3 (5.2) |
Pain intensity (VAS) in (mean ± sd) |
|
|
| 3.0 | 6.2 (1.9) |
Treatment during enrollment (%) |
|
|
| 23.6 | 76.7 |
Pain intensity at 3 months (VAS) (mean ± sd) |
|
|
| 17.8 | 4.5 (2.5) |
Functional status at 3 months (RDQ) (mean ± sd) |
|
|
| 19.9 | 8.8 (6.1) |
Change in pain intensity* (VAS) (mean ± sd) |
|
|
| 20.0 | 2.2 (2.8) |
Pain coping, active (mean ± sd) |
|
|
| 5.6 | 6.7 (1.2) |
Pain coping, passive (mean ± sd) |
|
|
| 7.0 | 6.5 (1.3) |
Fear avoidance beliefs (FAB) (mean ± sd) |
|
| Â | 48.1 | 19.5 (9.7) |
Kinesiophobia (Tampa) (mean ± sd) |
|
|
| 6.2 | 39.8 (6.7) |
Body mass index |
|
|
| 4.1 | 25.9 (4.0) |