Crude and adjusted PR (95% CI) for the association between 1 year prevalence of low back pain at follow up and work tasks or indices among 230 workers without low back pain at baseline
| Potential risk factor; specific task or index | 1 y Prevalence | Crude and adjusted PR (95% CI) | |||||||
|---|---|---|---|---|---|---|---|---|---|
| n | % | Crude estimate | Initial confounder4-150 | Initial confounder and job4-151 | |||||
| General tasks (h/shift): | |||||||||
| Scaffolding: | |||||||||
| 0 | 36/126 | 28.6 | 1 (reference) | 1 (reference) | 1 (reference) | ||||
| >0–<0.5 | 11/43 | 25.6 | 0.9 (0.5 to 1.8) | 0.9 (0.4 to 1.8) | 0.9 (0.4 to 2.0) | ||||
| 0.5–3.0 | 24/61 | 39.3 | 1.4 (0.8 to 2.3) | 1.4 (0.8 to 2.4) | 1.4 (0.8 to 2.6) | ||||
| Tasks of carpenters (h/shift): | |||||||||
| Sawing wood: | |||||||||
| 0 | 54/189 | 28.6 | 1 (reference) | 1 (reference) | 1 (reference) | ||||
| >0–1.0 | 8/14 | 57.1 | 2.0 (1.0 to 4.3) | 2.4 (1.1 to 5.2) | 1.7 (0.6 to 4.8) | ||||
| >1.0–4.0 | 7/17 | 41.2 | 1.5 (0.8 to 3.2) | 1.5 (0.7 to 3.5) | 1.0 (0.3 to 3.0) | ||||
| Erecting roof structures: | |||||||||
| 0 | 54/189 | 28.6 | 1 (reference) | 1 (reference) | 1 (reference) | ||||
| >0–0.7 | 8/21 | 38.1 | 1.3 (0.6 to 2.8) | 1.6 (0.7 to 3.5) | 1.1 (0.4 to 2.9) | ||||
| >0.7–4.0 | 9/20 | 45.0 | 1.6 (0.8 to 3.2) | 1.6 (0.8 to 3.3) | 0.9 (0.3 to 2.6) | ||||
| Laying defined brick/stone formats (h/shift): | |||||||||
| 3DF sandstone4-152: | |||||||||
| 0 | 49/170 | 28.8 | 1 (reference) | 1 (reference) | 1 (reference) | ||||
| >0–<2.0 | 9/29 | 31.0 | 1.1 (0.5 to 2.2) | 1.2 (0.6 to 2.5) | 1.8 (0.7 to 4.7) | ||||
| 2.0–8.5 | 13/31 | 41.9 | 1.5 (0.8 to 2.7) | 1.7 (0.9 to 3.1) | 2.6 (1.1 to 6.5) | ||||
| Stone indices: | |||||||||
| Stone load4-153: | |||||||||
| None | 42/140 | 28.7 | 1 (reference) | 1 (reference) | 1 (reference) | ||||
| Intermediate | 8/38 | 24.3 | 0.7 (0.3 to 1.5) | 0.8 (0.4 to 1.7) | 1.8 (0.3 to 9.3) | ||||
| High | 16/28 | 50.0 | 1.4 (0.8 to 2.5) | 1.6 (0.9 to 2.9) | 4.0 (0.8 to 19.8) | ||||
| Laying >3DF stones: | |||||||||
| No | 58/201 | 28.7 | 1 (reference) | 1 (reference) | 1 (reference) | ||||
| Yes | 13/29 | 44.8 | 1.7 (0.5 to 5.2) | 1.6 (0.5 to 5.1) | 1.7 (0.5 to 5.7) | ||||
↵4-150 Adjusted for age (⩽25/>25–30/>30–35/>35–40/>40–45/>45–50/>50), sitting height (cm), and body mass index (kg/m2); n=227 because of missing values for sitting height and body mass index.
↵4-151 Adjusted for five categories of occupation at baseline.
↵4-152 Subjects with missing values excluded (n=7/230).
↵4-153 Subjects with missing values excluded (n=4/230).