| Study characteristics |
| Methods |
Study design: RCT (NCT01303588)
Setting: Germany, general population
Exercise groups: 2
Comparison groups: 1 |
| Participants |
Number of participants: 176 (E1 = 61, E2 = 58, C1 = 57)
Chronic LBP duration: 18.79 years (long)
Neurological/radicular symptoms: Not specified
Mean age (years): 73
Sex (female): 89% |
| Interventions |
Exercise Group 1 (E1): Yoga; type = yoga; duration = 12 weeks; dose = low; design = partially individualised; delivery = group; additional intervention = none
Exercise Group 2 (E2): Qigong; type = other (Qigong); duration = 12 weeks; dose = low; design = standardised; delivery = group; additional intervention = manual therapy
Comparison Group 1 (C1): Usual care/no treatment (waiting‐list group) |
| Outcomes |
Core outcomes reported: Pain (Visual Analogue Scale); function (Hannover Functional Ability Questionnaire); HRQoL (36‐Item Short Form Survey)
Follow‐up time periods available for syntheses: 13 weeks (short); 26 weeks (moderate) |
| Notes |
Conflicts of interest: J.K. is a Viniyoga teacher trained by the Berliner Yoga Zentrum.
Funding source: Karl and Veronica Carstens Foundation
Other: Information modified for author contact; SDs imputed |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Random sequence generation (selection bias) |
Low risk |
Randomisation carried out with the 'ranuni' function of SAS software with a 1:1:1 ratio, stratified by participant housing (living in retirement home versus alone) and blocked with a fixed, unknown length. |
| Allocation concealment (selection bias) |
Low risk |
Randomisation list was held in a secure database, inaccessible to anyone involved in randomisation or treatment; allocation could not be changed or deleted, ensuring allocation concealment. |
| Blinding of participants and personnel (performance bias)
All outcomes |
Low risk |
1. Patients could not be blinded to allocation due to the nature of the treatments; 2. Unlikely that the lack of patient blinding caused deviations from the intended interventions, as patients had very little control over delivery of interventions |
| 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. Unlikely that lack of provider blinding caused significant deviations; each treatment group highly structured with distinct nature, yoga and qigong delivered by separate trained personnel |
| Blinding of outcome assessment (detection bias)
All outcomes |
High risk |
1. Outcome assessors for pain and function were patients themselves, who could not be blinded to allocation due to the nature of the treatments; 2. Pain and functional questionnaires are subjective, and responses could be altered by awareness of intervention; 3. Likely that lack of patient blinding caused bias in outcome assessments, as the Qigong and yoga groups were clearly "better" than the control; few clear results in support |
| Incomplete outcome data (attrition bias)
All outcomes |
Low risk |
1. At the 3‐month follow‐up, 12 participants were lost to follow‐up of 176. |
| Participants analysed in group allocated (attrition bias) |
Low risk |
1. "Outcomes were analyzed for the full analysis set, on the basis of the intention‐to‐treat principle". |
| Selective reporting (reporting bias) |
High risk |
1. Study was fully analysed and reported according to the registered trial protocol (NCT01303588), except that there was no Tinetti test results at 6 months nor adverse events reported; 2. Particularly for adverse events, it is suspicious that they were not reported and it was reasonably likely that they were not reported due to their unflattering results 3. There was no apparent reporting bias for the analytic method used in this study. |
| Groups similar at baseline (selection bias) |
Low risk |
Both treatment groups were similar on all relevant baseline characteristics. |
| Co‐interventions avoided or similar (performance bias) |
Low risk |
Excluded patients using central nervous system pain agents (e.g. opioids) or with preplanned start of physiotherapy within the study duration; there was no difference in pain medication use during study period. |
| Compliance acceptable in all groups (performance bias) |
Low risk |
Participated in 75% or more of classes = 74.1% (yoga), 72.7% (qigong) of patients; participated in 50 to 75% of classes = 12.9% (yoga), 18.2% (qigong) of patients |
| Timing of outcome assessment similar in all groups (detection bias) |
Low risk |
1. Outcome assessments were identical for all patients, regardless of treatment group; 2. Functional Rating Index (for pain) and the Hannover Functional Ability Questionnaire (for function) are well‐validated tools in the low back pain context. |
| Other bias |
Low risk |
Appeared free from other sources of bias |
