Table 4
Odds ratios (OR) for becoming a new symptom forearm case during follow up for those with no or mild symptoms at baseline
| OR (95% CI) | ||||
|---|---|---|---|---|
| Model I* n=4305 | Model II† n=4408 | Model III‡ n=4190 | Model IV§ n=4340 (64 cases) | |
| *Model including time variables and physical workplace factors. | ||||
| †Model including time variables and psychosocial factors. | ||||
| ‡Model including time variables and personal characteristics. | ||||
| §Final model, which includes time variables and all other parameters from model I to III with p<0.10. | ||||
| Physical workplace factors | ||||
| Hours per week with mouse in right hand | ||||
| 0–9 | 1 | 1 | 1 | 1 |
| 10–19 | 1.8 (0.9 to 3.9) | 2.2 (1.0 to 4.6) | 1.9 (0.9 to 4.1) | 2.2 (1.0 to 4.7) |
| 20–29 | 1.8 (0.7 to 4.6) | 2.5 (1.0 to 6.1) | 2.2 (0.9 to 5.7) | 2.6 (1.0 to 6.6) |
| ⩾30 | 6.8 (2.1 to 23) | 8.8 (2.6 to 29) | 6.8 (1.7 to 27) | 8.4 (2.5 to 29) |
| No arm support (mouse) | 1 | – | – | – |
| Arm support (mouse) <50% time | 0.4 (0.1 to 1.3) | – | – | – |
| Arm support (mouse) ⩾50% time | 0.7 (0.3 to 2.0) | – | – | – |
| Abnormal mouse position | 1.5 (0.6 to 3.6) | – | – | – |
| Keyboard time in hours per week | ||||
| 0–4 | 1 | 1 | 1 | 1 |
| 5–9 | 1.3 (0.5 to 3.2) | 1.2 (0.5 to 3.0) | 1.8 (0.7 to 4.8) | 1.2 (0.5 to 2.9) |
| 10–14 | 1.4 (0.5 to 3.7) | 1.4 (0.5 to 3.6) | 2.0 (0.7 to 5.8) | 1.3 (0.5 to 3.4) |
| ⩾15 | 2.4 (0.9 to 6.7) | 2.4 (0.9 to 6.6) | 2.6 (0.8 to 8.4) | 2.6 (0.9 to 7.3) |
| No arm support (keyboard) | 1 | – | – | – |
| Arm support (keyboard) <50% time | 1.1 (0.5 to 2.5) | – | – | – |
| Arm support (keyboard) ⩾50% time | 1.2 (0.6 to 2.3) | – | – | – |
| Abnormal keyboard position | 1.2 (0.6 to 2.6) | – | – | – |
| Not satisfied with workplace design | 1.1 (0.4 to 2.7) | – | – | – |
| Work chair not adjusted | 0.8 (0.1 to 6.0) | – | – | – |
| Work desk not adjusted | 0.6 (0.3 to 1.4) | – | – | – |
| Psychosocial workplace factors | ||||
| High demands | – | 1.8 (1.0 to 3.3) | – | 1.9 (1.0 to 3.4) |
| Low control | – | 1.0 (0.5 to 1.7) | – | |
| Low social support | – | 1.1 (0.6 to 2.0) | – | |
| Time pressure | – | 1.8 (1.0 to 3.3) | – | 1.7 (0.9 to 3.1) |
| Personal characteristics | ||||
| Negative affectivity | – | – | 1.8 (0.9 to 3.7) | 1.6 (0.8 to 3.1) |
| Type A behaviour | – | – | 1.3 (0.5 to 3.0) | – |
| Age (10 years increment) | – | – | 1.4 (1.0 to 1.9) | 1.4 (1.1 to 2.0) |
| Female gender | – | – | 1.9 (0.9 to 4.1) | 2.2 (1.1 to 4.5) |
| BMI <19 kg/m2 | – | – | 1.1 (0.3 to 4.7) | – |
| BMI ⩾27 kg/m2 | – | – | 0.7 (0.2 to 2.9) | – |
| Poor social network | – | – | 1.3 (0.5 to 3.1) | – |
| High physical leisure activity | – | – | 0.6 (0.3 to 1.1) | – |
| Chronic disease | – | – | 2.0 (0.8 to 4.9) | – |
| Pain started after accident | – | – | 2.4 (0.6 to 10) | – |
| Hosmer-Lemeshow’s goodness of fit test with 10 groups: p value | 0.70 | 0.66 | 0.76 | 0.14 |
