| Study characteristics |
| Methods |
Study design: RCT
Setting: Switzerland, occupational
Exercise groups: 1
Comparison groups: 1 |
| Participants |
Number of participants: 148 (E1 = 74, C1 = 74)
Chronic LBP duration: 12 years (long)
Neurological/radicular symptoms: Some participants
Mean age (years): 39
Sex (female): Not reported |
| Interventions |
Exercise Group 1 (E1): Static and dynamic strengthening exercises (1st phase, 1‐4 weeks), Norsk machines for strength and endurance (2nd phase, 5‐8 weeks), sequence training (3rd phase, 9‐12 weeks); type = strengthening; duration = 12 weeks; dose = high; design = partially individualised; delivery = group; additional intervention = back school
Comparison Group 1 (C1): Other conservative treatment (back school) |
| Outcomes |
Core outcomes reported: Pain (Numeric Rating Scale); function (Roland‐Morris Disability Questionnaire)
Follow‐up time periods available for syntheses: 12 weeks (short); 26 weeks (moderate); 52 weeks (long) |
| Notes |
Conflicts of interest: Not reported
Funding source: Swiss National Science Foundation (Project NFP 26, No. 4026‐27064); BBW (Project ‘‘SOS‐LBD’’, No. 97.0046)
Other: None |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Random sequence generation (selection bias) |
Low risk |
Prior to a first contact they were randomly assigned to the exercise or comparison group by means of a computer randomisation program. |
| Allocation concealment (selection bias) |
High risk |
Not described |
| Blinding of participants and personnel (performance bias)
All outcomes |
High risk |
Not described |
| Blinding of care provider (performance bias) |
High risk |
Not described |
| Blinding of outcome assessment (detection bias)
All outcomes |
High risk |
Prior to the start of the intervention study all participants were thoroughly examined and completed several functional tests and questionnaires. |
| Incomplete outcome data (attrition bias)
All outcomes |
Unclear risk |
The total number of subjects who finally participated in the study was 183. |
| Participants analysed in group allocated (attrition bias) |
High risk |
For analysis, only subjects that had completed the intervention programme were considered. |
| Selective reporting (reporting bias) |
Low risk |
Support for judgement was not available. |
| Groups similar at baseline (selection bias) |
Low risk |
Baseline characteristics did not differ for low back pain symptoms and demographic variables. |
| Co‐interventions avoided or similar (performance bias) |
Unclear risk |
Not described |
| Compliance acceptable in all groups (performance bias) |
Low risk |
Not described |
| Timing of outcome assessment similar in all groups (detection bias) |
Low risk |
Support for judgement was not available. |
