Table 4.
Results from multivariate analysis. Presenting the effect of difficulties initiating sleep, difficulties maintaining sleep, early morning awakening, non-restorative sleep and fatigue on the odds ratio (OR) for reporting CWP in the 5-year and 18-year follow-up respectively. The OR, 95% confidence intervals (95% CI) and p-value (p) are presented in model 1–3. N = 1249 entered the 5-year follow-up analyses; N = 791 entered in the 18-year follow-up analyses
| Adjusted for age gender, mental healthc, socio-economyd | Adjusted for age, gender, socio-economydand number of pain sites | Adjusted for age, gender, socio-economyd, mental healthc and number of pain sites | ||||
|---|---|---|---|---|---|---|
| CWP 5-year | CWP 18-year | CWP 5-year | CWP 18-year | CWP 5-year | CWP 18-year | |
| OR (95% CI) | OR (95% CI) | OR (95% CI) | OR (95% CI) | OR (95% CI) | OR (95% CI) | |
| Initiating sleepa | ||||||
| No Problem | 1 | 1 | 1 | 1 | 1 | 1 |
| Problem | 1.91 (1.16–3.14)* | 1.93 (1.18–3.18)* | 1.71 (1.03–2.85)* | 1.68 (1.00–2.81) | 1.37 (0.81–2.34) | 1.51 (0.89–2.57) |
| Maintaining Sleepa | ||||||
| No problem | 1 | 1 | 1 | 1 | 1 | |
| Problem | 1.85 (1.14–3.01)* | 2.25 (1.40–3.61)* | 1.60 (0.98–2.63) | 1.88 (1.16–3.05)* | 1.32 (0.79-2.21) | 1.72 (1.05–2.84)* |
| Early awakeninga | ||||||
| No problem | 1 | 1 | 1 | |||
| Problem | 2.00 (1.23–3.27)* | 1.54 (0.94–2.54) | 1.71 (1.04–2.83)* | 1.32 (0.79–2.21) | 1.45 (0.86–2.43) | 1.18 (0.69–2.01) |
| Non-restorativea | ||||||
| No problem | 1 | 1 | 1 | 1 | ||
| Problem | 2.27 (1.37–3.75)* | 2.04 (1.26–3.29)* | 1.90 (1.15–3.13)* | 1.57 (0.97–2.56) | 1.51 (0.88–2.58) | 1.39 (0.83–2.34) |
| Fatigueb | ||||||
| Low | 1 | 1 | 1 | 1 | 1 | 1 |
| Intermediate | 1.75 (0.83–3.66) | 1.09 (0.60–2.00) | 1.71 (0.84–3.45) | 1.05 (0.59–1.89) | 1.48 (0.70–3.15) | 0.97 (0.52–1.79) |
| High | 3.70 (1.76–7.84)* | 2.36 (1.24–4.50)* | 2.59 (1.34–3.47)* | 1.62 (0.92–2.85) | 1.93 (0.87–4.26) | 1.34 (0.69–2.68) |
aProblems = [Moderate problems - very severe problems]; No Problems = [no problems - minor problems]. b Based on scorings on SF-36 vitality scale [Low = 85–100; Intermediate = 70–84; High = 0–69]; cBased on scorings on SF-36 Mental Health scale [Good = 93–100; Intermediate = 84–92; Poor = 0–83]; dClassified by occupation – intermediate/higher non-manual employees, Assistant non-manual employees, Manual workers and “others”
*p < 0.05