Descriptive characteristics of the study population (n=748)
| N | Median | IQR | Mean | SD | |
| Age (years) | 748 | 44.8 | 9.6 | ||
| Men N (%) | 411 (55) | ||||
| BMI (kg/m2) | 732 | 27.3 | 4.8 | ||
| Seniority (years) | 722 | 13.5 | 10.3 | ||
| Administration workers N (%) | 128 (17) | ||||
| Blue-collar workers N (%) | 620 (83) | ||||
| Cleaning | 115 (15) | ||||
| Manufacturing | 448 (60) | ||||
| Transportation | 57 (8) | ||||
| Physical work load at baseline (scale 1–10) | 723 | 5.3 | 2.4 | ||
| Sick leave days | |||||
| Baseline (days/month) | 741 | 0.0 | 0.0 | 0.3 | 1.9 |
| Last follow-up (days/month) | 655 | 0.0 | 0.0 | 0.4 | 2.5 |
| Total days (over all time points) | 746 | 0.0 | 3.0 | 5.8 | 20.9 |
| Work ability (scale 0–10) | |||||
| Baseline | 646 | 9.0 | 2.0 | 8.5 | 2.0 |
| Last follow-up | 671 | 9.0 | 2.0 | 8.2 | 2.4 |
| Mean work ability (over all time points) | 732 | 8.8 | 2.5 | 8.3 | 1.7 |
| NSP intensity (scale 0–10) | |||||
| Baseline | 748 | 2.0 | 5.0 | 3.0 | 2.7 |
| Last follow-up | 652 | 2.0 | 4.0 | 2.4 | 2.7 |
| Mean NSP intensity (over all time points) | 748 | 2.0 | 3.6 | 2.6 | 2.3 |
| Number of pain regions at baseline (count) | 745 | 1.0 | 3.0 | 1.7 | 1.5 |
| Compliance to text messages (missing responses, count) | |||||
| NSP intensity | 748 | 0.0 | 1.0 | 1.2 | 2.7 |
| Sick leave | 746 | 0.0 | 1.0 | 1.2 | 2.6 |
| Work ability | 732 | 0.0 | 1.0 | 0.4 | 0.7 |
BMI, body mass index; NSP, neck–shoulder pain.