Variable at baseline | n | LBP at t1 | RR | 95% CI | p Value* | ||
---|---|---|---|---|---|---|---|
n | % | ||||||
RR, relative risk; 95% CI, 95% confidence interval. | |||||||
*Calculated with χ^{2} tests. | |||||||
Pushing or pulling heavy loads | No | 322 | 31 | 9.6 | 1.00 | 0.077 | |
<1 time/hour | 201 | 27 | 13.4 | 1.40 | (0.86–2.27) | ||
⩾1 time/hour | 183 | 30 | 16.4 | 1.70 | (1.07–2.72) | ||
Lifting or carrying loads | No | 122 | 12 | 9.8 | 1.00 | 0.430 | |
⩽10 kg | 83 | 11 | 13.3 | 1.35 | (0.62–2.91) | ||
>10 kg, ⩽25 kg, ⩽12 times/hour | 122 | 15 | 12.3 | 1.25 | (0.61–2.56) | ||
>10 kg, ⩽25 kg, >12 times/hour | 50 | 7 | 14.0 | 1.42 | (0.60–3.40) | ||
>25 kg, ⩽12 times/hour | 310 | 39 | 12.6 | 1.28 | (0.69–2.36) | ||
>25 kg, >12 times/hour | 13 | 4 | 30.8 | 3.13 | (1.18–8.33) |