| Study characteristics |
| Methods |
Study design: RCT
Setting: Brazil, healthcare
Exercise groups: 2
Comparison groups: 0 |
| Participants |
Number of participants: 43 (E1 = 23, E2 = 20)
Chronic LBP duration: 82.62 months (long)
Neurological/radicular symptoms: Not specified
Mean age (years): 51
Sex (female): 79% |
| Interventions |
Exercise Group 1 (E1): Global posture re‐education: patients hold 3 different positions (statically) for 15 minutes each; type = core strengthening; duration = 6 weeks; dose = low; design = individualised; delivery = individual; additional intervention = none
Exercise Group 2 (E2): Isostretching: cycles of holding 9 different postures for 9 breaths each, with 60‐second rest between each cycle; type = stretching; duration = 6 weeks; dose = low; design = individualised; delivery = individual; additional intervention = none |
| Outcomes |
Core outcomes reported: Pain (Visual Analogue Scale); function (Roland‐Morris Disability Questionnaire)
Follow‐up time periods available for syntheses: 6 weeks (short) |
| Notes |
Conflicts of interest: Not reported
Funding source: Not reported
Other: None |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Random sequence generation (selection bias) |
Low risk |
Randomisation was done through computer‐generated numbers and delivered in sealed, opaque envelopes numbered in sequence. |
| Allocation concealment (selection bias) |
Low risk |
Sealed, opaque envelopes |
| Blinding of participants and personnel (performance bias)
All outcomes |
Low risk |
1. Impossible for patients to be blinded to different exercise protocols; 2. Two treatments were similar; patients likely did not have expectations about which treatment would be more effective and thus their expectations of effectiveness would be unbiased. |
| Blinding of care provider (performance bias) |
Low risk |
1. Care providers could not be blinded to allocation due to the nature of the treatments; 2. Same care provider conducted both active treatments; protocol was explicit, no decision‐making by personnel; opinion may have transferred to patients but no clear better intervention |
| Blinding of outcome assessment (detection bias)
All outcomes |
Unclear risk |
1. Outcomes in question were pain and function which were assessed by the patients who were not blinded; 2. Pain and functional questionnaires are subjective, and responses could be altered by awareness of intervention; 3. Neither treatment was obviously better than the other; no reason to alter patient response |
| Incomplete outcome data (attrition bias)
All outcomes |
Low risk |
1. Dropout rate was = > 0% in both treatment groups; one dropout was due to a change of address. |
| Participants analysed in group allocated (attrition bias) |
Unclear risk |
1. Explicitly stated that intent‐to‐treat analysis was not performed; It was deemed unnecessary due to the low dropout rate; 2. No mention of patients switching groups; dropout rate was sufficiently small that the missing data (and lack of intention‐to‐treat analysis) was unlikely to have affected overall conclusions. |
| Selective reporting (reporting bias) |
Low risk |
1. All study outcomes were fully analysed according to trial registration (NCT01468298). |
| Groups similar at baseline (selection bias) |
Low risk |
A few characteristics were collected and similar; no indication of problematic randomisation |
| Co‐interventions avoided or similar (performance bias) |
High risk |
Co‐interventions not reported; no mention of medications and whether or not participants were allowed to use other forms of treatment during treatment |
| Compliance acceptable in all groups (performance bias) |
High risk |
No adherence reporting but limitations listed compliance as a difficulty; all treatment sessions were supervised, and thus compliance could have been reported. |
| Timing of outcome assessment similar in all groups (detection bias) |
Low risk |
1. All outcomes assessments were performed identically for participants in both treatment groups; data collection was performed at the same time for both treatment groups and with the same tools; 2. Visual Analogue Scale and Roland‐Morris Disability Questionnaire are very commonly used in low back pain studies and have been validated in this context. |
| Other bias |
Low risk |
Under‐reported, no other apparent sources of bias |
