Table 2.
Baseline characteristics of the study participants. Means (SD = standard deviation) or percentages when applicable
| Characteristics | Rehab (n = 43) | Physio (n = 43) | Advice (n = 40) | Control (n = 50) | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| % | mean | SD | % | mean | SD | % | mean | SD | % | mean | SD | p | |
| Demographic features | |||||||||||||
| Age, years | . | 45 | 9 | . | 44 | 8 | . | 45 | 7 | . | 46 | 7 | 0.44 |
| Male, % | 65 | . | . | 72 | . | . | 68 | . | . | 60 | . | . | 0.30 |
| High School diploma/vocational degree, % | 67 | . | . | 56 | . | . | 58 | . | . | 70 | . | . | 0.23 |
| Health related features | |||||||||||||
| Duration of LBP, years | . | 13 | 9 | . | 10 | 9 | . | 14 | 9 | . | 11 | 9 | 0.51 |
| Smoking, % | 31 | . | . | 40 | . | . | 40 | . | . | 23 | . | . | 0.14 |
| Work-related features | |||||||||||||
| Blue collar worker, % | 74 | . | . | 77 | . | . | 90 | . | . | 84 | . | . | 0.56 |
| Shift workera, % | 43 | . | . | 28 | . | . | 39 | . | . | 32 | . | . | 0.68 |
| Physical workload (1–5)b | . | 3 | 1 | . | 3 | 1 | . | 3 | 1 | . | 3 | 1 | 0.48 |
| Mental workload (1–5)b | . | 3 | 1 | . | 3 | 1 | . | 3 | 1 | . | 3 | 1 | 0.07 |
| Work ability (0–10)c | . | 7 | 2 | . | 7 | 2 | . | 7 | 2 | . | 7 | 2 | 0.84 |
| Total SA days/previous year | . | 16 | 23 | . | 21 | 28 | . | 19 | 26 | . | 22 | 49 | 0.62 |
| Total SA periods/previous year | . | 4 | 5 | . | 4 | 4 | . | 4 | 4 | . | 4 | 5 | 0.99 |
| Low back specific SA days/previous year | . | 6 | 14 | . | 9 | 25 | . | 9 | 22 | . | 9 | 41 | 0.92 |
| Outcome variables at baseline | |||||||||||||
| LBP intensity, LBP (0–100) | . | 60 | 17 | . | 55 | 14 | . | 60 | 18 | . | 60 | 18 | 0.47 |
| Physical impairment, PHI (0–18) | . | 8 | 5 | . | 8 | 5 | . | 8 | 5 | . | 7 | 5 | 0.19 |
| Pain related fear, FABQ (13–78) | . | 38 | 14 | . | 38 | 12 | . | 37 | 12 | . | 35 | 12 | 0.26 |
| FABQ work, FABQw (6–36) | . | 18 | 7 | . | 16 | 7 | . | 16 | 7 | . | 16 | 7 | 0.61 |
| FABQ physical activity, FABQph (4–24) | . | 13 | 5 | . | 14 | 5 | . | 13 | 5 | . | 12 | 4 | 0.09 |
atwo-shift or three-shift work
bself rated workload: 1 = very heavy, 2 = moderate, 3 = intermediate, 4 = rather light, 5 = very light
crange 0–10 from the lowest possible work ability (0) to the best possible work ability (10)
The three intervention groups were pooled for the comparison with the Control group and P denotes the p-value of the comparison. Range (when applicable) is presented after the variable name in the parenthesis
Rehab outpatient rehabilitation at the physical medicine unit, Physio progressive back-specific exercises, Advice self-care advice by an OH physician, Control Natural course control group, SA sickness absence, LBP low back pain, VAS Visual Analogue Scale, PHI physical impairment by the Roland-Morris Disability Questionnaire (0 to 18), FABQ Fear Avoidance Beliefs questionnaire, FABQw Fear Avoidance beliefs questionnaire, work subscale, FABQph Fear Avoidance beliefs questionnaire, physical activity subscale