Table 3.
Biomechanical exposure and risk of CTS, (i) unadjusted for work psychosocial exposure, and adjusted for: (ii) Job Strain Ratio (iii) Psychological Demand, and (iv) Decision Latitude. All models (i-iv) are adjusted for age, gender, BMI, study site and dissimilar biomechanical exposures9.
| Cutoffs | Cohort | Cases | (i) Unadjusted for Psychosocial Factors HR (95% CI) |
(ii) adj. for Job Strain Ratio HR (95% CI) |
(iii) adj. for Psychological Demand HR (95% CI) |
(iv) adj. for Decision Latitude HR (95% CI) |
|||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Peak Force (CR-10) | 1109 | 79 | |||||||||
| Lower Half | ≤ 3 | 42 | 1.00 | - | 1.00 | - | 1.00 | - | 1.00 | - | |
| Upper Half | >3 | 37 | 1.38 | (0.85–2.26) | 1.30 | (0.79–2.13) | 1.37 | (0.84–2.24) | 1.28 | (0.78–2.08) | |
| Total Repetition Rate | 1109 | 79 | |||||||||
| Lower Half | ≤ 16.4 | 47 | 1.00 | - | 1.00 | - | 1.00 | - | 1.00 | - | |
| Upper Half | > 16.4 | 32 | 1.03 | (0.61–1.74) | 0.96 | (0.57–1.62) | 1.01 | (0.60–1.70) | 0.97 | (0.57–1.65) | |
| % Time All Exertions | 1109 | 79 | |||||||||
| Lower Half | ≤ 68% | 38 | 1.00 | - | 1.00 | - | 1.00 | - | 1.00 | - | |
| Upper Half | > 68% | 41 | 1.18 | (0.75–1.88) | 1.19 | (0.75–1.89) | 1.19 | (0.75–1.90) | 1.16 | (0.73–1.84) | |
| HAL Scale | 1370 | 90 | |||||||||
| Lower Half | ≤ 4.4 | 41 | 1.00 | - | 1.00 | - | 1.00 | - | 1.00 | - | |
| Upper Half | > 4.4 | 49 | 1.90 | (1.17–3.10) | 1.82 | (1.12–2.97) | 1.89 | (1.16–3.07) | 1.79 | (1.09–2.93) | |
| Forceful Repetition Rate | 1423 | 92 | |||||||||
| Lower Half | ≤ 4.9 | 51 | 1.00 | - | 1.00 | - | 1.00 | - | 1.00 | - | |
| Upper Half | > 4.9 | 41 | 1.41 | (0.87–2.30) | 1.26 | (0.75–2.12) | 1.35 | (0.82–2.24) | 1.23 | (0.74–2.05) | |
| % Time Forceful Exertions | 1423 | 92 | |||||||||
| Lower Half | ≤ 19% | 43 | 1.00 | - | 1.00 | - | 1.00 | - | 1.00 | - | |
| Upper Half | > 19% | 49 | 2.17 | (1.36–3.46) | 2.03 | (1.26–3.26) | 2.11 | (1.32–3.39) | 1.95 | (0.62–1.96) | |
| ACGIH TLV for HAL | 1390 | 95 | |||||||||
| Lower Half | ≤ 0.56 | 41 | 1.00 | - | 1.00 | - | 1.00 | - | 1.00 | - | |
| Upper Half | > 0.56 | 54 | 1.85 | (1.20–2.86) | 1.71 | (1.10–2.66) | 1.84 | (1.19–2.84) | 1.68 | (1.07–2.62) | |