Table 5.
Categorical relationships of 12-month low-back pain (LBP) outcomes to alternative measures of cumulative lifetime vibration dose (quartile based design variables) among professional drivers (N=537, observations=854). See table 2 for the definitions of measures of cumulative lifetime vibration dose. [OR=odds ratio; CI=confidence interval.]
| Measures of vibration dose | LBP | Chronic LBP | Sciatic pain | ||||||
|---|---|---|---|---|---|---|---|---|---|
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| OR (95% CI) a,b | 2 test for trend (P-value) | QIC (Δ) c | OR (95% CI) a,b | 2 test for trend (P-value) | QIC (Δ) c | OR (95% CI) a,b | 2 test for trend (P-value) | QIC (Δ) c | |
| ∑[awz2t] (×107 m2s-3) | 5.44 (0.020) | 742 (0) | 4.82 (0.028) | 521 (0) | 13.0 (0.0003) | 989 (0) | |||
| 0.006–0.57 | 1.0 (–) | 1.0 (–) | 1.0 (–) | ||||||
| 0.58–1.34 | 0.95 (0.50–1.80) | 0.90 (0.38–2.14) | 0.72 (0.41–1.27) | ||||||
| 1.35–2.70 | 1.18 (0.62–2.24) | 1.06 (0.48–2.35) | 1.84 (1.09–3.14) | ||||||
| 2.71–11.7 | 1.92 (1.05–3.53) | 2.25 (1.05–4.81) | 2.30 (1.34–3.94) | ||||||
| ∑[A(8)z2t] (×103 m2s-4) | 6.52 (0.011) | 740 (–2) | 5.13 (0.024) | 520 (–1) | 11.7 (0.0006) | 990 (1) | |||
| 0.003–0.197 | 1.0 (–) | 1.0 (–) | 1.0 (–) | ||||||
| 0.198–0.493 | 0.77 (0.40–1.50) | 0.81 (0.34–1.97) | 0.75 (0.42–1.32) | ||||||
| 0.494–0.920 | 1.03 (0.54–1.98) | 1.06 (0.48–2.34) | 1.69 (0.99–2.89) | ||||||
| 0.921–3.774 | 2.06 (1.10–3.85) | 2.39 (1.08–5.29) | 2.30 (1.32–4.02) | ||||||
| ∑[Ftotal,rms2t] (×1011 N2s) | 7.02 (0.008) | 738 (–4) | 9.84 (0.002) | 513 (–8) | 14.0 (0.0002) | 983 (–6) | |||
| 0.001–0.17 | 1.0 (–) | 1.0 (–) | 1.0 (–) | ||||||
| 0.18–0.45 | 0.88 (0.46–1.67) | 1.03 (0.43–2.50) | 1.04 (0.60–1.79) | ||||||
| 0.46–1.01 | 1.36 (0.72–2.56) | 1.56 (0.67–3.61) | 1.91 (1.12–3.24) | ||||||
| 1.02–3.57 | 2.31 (1.17–4.56) | 3.81 (1.60–9.10) | 2.84 (1.55–5.21) | ||||||
| ∑[Ftotal,rmst] (×109 Ns) | 7.33 (0.007) | 738 (–4) | 9.18 (0.0025) | 515 (–6) | 18.7 (0.0001) | 975 (–14) | |||
| 0.01–0.83 | 1.0 (–) | 1.0 (–) | 1.0 (–) | ||||||
| 0.84–1.82 | 1.23 (0.65–2.35) | 1.26 (0.53–2.98) | 0.97 (0.56–1.70) | ||||||
| 1.83–3.25 | 1.32 (0.69–2.52) | 1.35 (0.57–3.21) | 2.14 (1.26–3.65) | ||||||
| 3.26–8.15 | 2.69 (1.33–5.42) | 4.12 (1.70–10.0) | 3.63 (1.94–6.80) | ||||||
| ∑[Fd,total,peak t1/6] (×103 N) | 5.33 (0.021) | 740 (–2) | 4.79 (0.029) | 521 (0) | 11.1 (0.0009) | 988 (–1) | |||
| 0.48–1.37 | 1.0 (–) | 1.0 (–) | 1.0 (–) | ||||||
| 1.38–1.94 | 0.59 (0.30–1.17) | 0.45 (0.16–1.25) | 0.96 (0.60–1.63) | ||||||
| 1.95–2.55 | 1.03 (0.55–1.95) | 0.94 (0.44–2.02) | 1.46 (0.86–2.48) | ||||||
| 2.56–3.96 | 2.17 (1.10–4.29) | 2.46 (1.12–5.43) | 2.57 (1.47–4.50) | ||||||
| ∑[Sedpeak t1/6] (MPa) | 3.09 (0.079) | 744 (2) | 3.33 (0.068) | 523 (2) | 8.63 (0.0033) | 991 (2) | |||
| 0.26–0.75 | 1.0 (–) | 1.0 (–) | 1.0 (–) | ||||||
| 0.76–1.08 | 0.77 (0.41–1.43) | 0.60 (0.24–1.46) | 1.05 (0.62–1.78) | ||||||
| 1.09–1.43 | 1.09 (0.58–2.04) | 0.99 (0.46–2.15) | 1.29 (0.76–2.19) | ||||||
| 1.44–2.23 | 1.71 (0.87–3.38) | 2.15 (0.95–4.87) | 2.47 (1.39–4.36) | ||||||
∑[awz2t], ∑[A(8)z2t]: OR adjusted by age-at-entry, body mass index, physical work load, psychosocial work environment, and follow up time.
∑[Ftotal,rms2t] to ∑[Sedpeak t1/6]: OR adjusted by age-at-entry, physical work load, psychosocial work environment, and follow up time.
QIC is the quasi-likelihood information criterion for the comparison between models. QIC difference (Δ) is calculated as the difference between the QIC value for a specific exposure model and the model including ∑[awz2t] calculated according to a second power time dependency.