Table 1.
Characteristics of the prospective cohort (n = 341)
| Variable | Total (n) | Frequency (%) | Mean (95% CI) |
|---|---|---|---|
| Sex | 341 | . | . |
| Women | . | 153 (44.9%) | . |
| Men | . | 188 (55.1%) | . |
| Age (in years) | 341 | . | 52.35 (51.84-52.86) |
| Occupation (SES) | 337 | . | . |
| Non manual | . | 185 (54.9%) | . |
| Manual | . | 112 (33.2%) | . |
| Self-employed | . | 40 (11.9%) | . |
| Smoking, current | 332 | 69 (20.8%) | . |
| BMI (kg/m2) | 340 | . | 26.11 (25.70-26.52) |
| Alcohol consumption | 325 | . | . |
| Lowa | . | 264 (81.2%) | . |
| Mediumb | . | 36 (11.1%) | . |
| Highc | . | 25 (7.7%) | . |
| Disease (self report of diagnosis) | 341 | 171 (50.2%) | . |
| Previous back pain | 330 | 219 (66.4%) | . |
| "Poor" work ability | 278 | 56 (20.1%) | . |
| Sickness absence spells at baseline† | 341 | . | 0.47 (0.39-0.55) |
| Sickness absence spells at follow-up‡ | 340 | . | 0.49 (0.42-0.56) |
| Sickness absence days at baseline† | 335 | . | 6.59 (4.83-8.35) |
| Sickness absence days at follow-up‡ | 340 | . | 6.96 (5.09-8.83) |
CI = confidence interval.
aLow (< 80 g/week for women, < 110 g/week for men)
bMedium (between 80-139 g/week for women, 110-169 g/week for men)
cHigh (≥ 140 g/week for women, ≥ 170 g/week for men)
† within the last 12 months before baseline
‡ within the last 12 months before follow-up