| Study characteristics |
| Methods |
Study design: RCT
Setting: Norway, occupational
Exercise groups: 2
Comparison groups: 1 |
| Participants |
Number of participants: 208 (E1 = 71, E2 = 70, C1 = 67)
Chronic LBP duration: 327 weeks (long)
Neurological/radicular symptoms: No participants
Mean age (years): 42
Sex (female): 50% |
| Interventions |
Exercise Group 1 (E1): Medical Exercise Therapy: mobilising and strengthening with special equipment, aerobic exercise warm‐up; type = mixed; duration = 12 weeks; dose = high; design = individualised; delivery = group; additional intervention = none
Exercise Group 2 (E2): Ordinary activity level: walking exercise programme; type = aerobic; duration = 12 weeks; dose = low; design = standardised; delivery = independent; additional intervention = none
Comparison Group 1 (C1): Other conservative treatment (physical therapy) |
| Outcomes |
Core outcomes reported: Pain (Visual Analogue Scale); function (Oswestry Disability Index); work (return to work at 1 year)
Follow‐up time periods available for syntheses: 12 weeks (short); 52 weeks (long) |
| Notes |
Conflicts of interest: Device status category: 1
Funding source: Ministry of Health and Social Affairs, Norwegian national budget (chapter no. 0720. 63/97, project no. 103 10); programme trygd og rehabilitering (May 1993‐June 1997); Foundation for Education and Research in Physiotherapy, Norway (July 1997‐ December 1997)
Other: SDs imputed |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Random sequence generation (selection bias) |
Low risk |
The randomisation sequence was computer‐generated by an independent data manager and was stratified by participants prespecified availability. |
| Allocation concealment (selection bias) |
Low risk |
Eligible participant details were entered into a randomisation database by the trial co‐ordinators and secretary, who were blinded to the allocation. |
| Blinding of participants and personnel (performance bias)
All outcomes |
High risk |
Assumed not possible |
| Blinding of care provider (performance bias) |
High risk |
Assumed not possible |
| Blinding of outcome assessment (detection bias)
All outcomes |
Low risk |
Questionnaires were posted with a prepaid envelope. Nonresponders were initially followed up with postal reminders and then with a telephone call. |
| Incomplete outcome data (attrition bias)
All outcomes |
Low risk |
Discussed in Figure and seemed similar across the two groups |
| Participants analysed in group allocated (attrition bias) |
Low risk |
Author contact: author referred to consort diagram; no confirmation of ITT |
| Selective reporting (reporting bias) |
Low risk |
Support for judgement was not available. |
| Groups similar at baseline (selection bias) |
Low risk |
Support for judgement was not available. |
| Co‐interventions avoided or similar (performance bias) |
Low risk |
Author contact: still unclear, did not look at co‐interventions |
| Compliance acceptable in all groups (performance bias) |
Low risk |
Sixty per cent of participants offered yoga adhered to the programme: of the remaining participants, 26% attended at least one class but did not fully adhere. |
| Timing of outcome assessment similar in all groups (detection bias) |
Low risk |
Support for judgement was not available. |
