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 baselinenLBP at t1Univariate analyses*Multivariate analyses†AF exposedAF total
n%RR95% CIp ValueRR95% CIp ValueAF95%CIAF95% CI
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.
Physical work factors
Working with the trunk in bent and twisted positionNo3824010.51.000.0201.000.038
⩽2 hours/day1462215.11.44(0.86–2.42)1.30(0.77–2.20)
>2 hours/day571424.62.35(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 regularlyYes5125610.91.00<0.0011.000.005
No732027.42.51(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 inclusionNo295289.51.000.0191.000.027
Yes2904816.61.74(1.09–2.78)1.71(1.07–2.75)
Pain related fearLow1942010.31.000.0061.000.013
Medium201189.00.87(0.46–1.64)0.85(0.45–1.60)
High1903820.01.94(1.13–3.33)1.81(1.04–3.14)0.45(0.04–0.68)0.21(0.01–0.41)