Table 5 Risk factors for low back pain lasting seven or more consecutive days after one year of follow up (LBP at t1).
| Variable at baseline | n | LBP at t1 | Univariate analyses* | Multivariate analyses† | AF exposed | AF total | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| n | % | RR | 95% CI | p Value | RR | 95% CI | p Value | AF | 95%CI | AF | 95% CI | |||||
| Physical work factors | ||||||||||||||||
| Working with the trunk in bent and twisted position | No | 382 | 40 | 10.5 | 1.00 | 0.020 | 1.00 | 0.038 | ||||||||
| ⩽2 hours/day | 146 | 22 | 15.1 | 1.44 | (0.86–2.42) | 1.30 | (0.77–2.20) | |||||||||
| >2 hours/day | 57 | 14 | 24.6 | 2.35 | (1.28–4.31) | 2.21 | (1.20–4.07) | 0.55 | (0.17–0.75) | 0.11 | (0.02–0.23) | |||||
| Ability to change posture regularly | Yes | 512 | 56 | 10.9 | 1.00 | <0.001 | 1.00 | 0.005 | ||||||||
| No | 73 | 20 | 27.4 | 2.51 | (1.50–4.17) | 2.11 | (1.26–3.54) | 0.53 | (0.21–0.72) | 0.12 | (0.03–0.24) | |||||
| Individual variables | ||||||||||||||||
| Back complaints in the year before inclusion | No | 295 | 28 | 9.5 | 1.00 | 0.019 | 1.00 | 0.027 | ||||||||
| Yes | 290 | 48 | 16.6 | 1.74 | (1.09–2.78) | 1.71 | (1.07–2.75) | |||||||||
| Pain related fear | Low | 194 | 20 | 10.3 | 1.00 | 0.006 | 1.00 | 0.013 | ||||||||
| Medium | 201 | 18 | 9.0 | 0.87 | (0.46–1.64) | 0.85 | (0.45–1.60) | |||||||||
| High | 190 | 38 | 20.0 | 1.94 | (1.13–3.33) | 1.81 | (1.04–3.14) | 0.45 | (0.04–0.68) | 0.21 | (0.01–0.41) | |||||
RR, relative risk; 95% CI, 95% confidence interval; AFexposed, attributable fraction among the exposed workers; AFtotal, total attributable fraction for the entire study population.
*Cox regression.
†Cox regression, backward selection, Pin = 0.20, Pout = 0.05.
Results from the model with no missing values (n = 585) for standing work for long periods, regular recreational sports, possibilities to develop skills, psychological job demands, perceived general health, family situation, body mass index, complaints of the lower limbs in the year before inclusion, age, sex, and the factors mentioned in the table.