| Methods |
Design: three group parallel trial
Purpose: study the effect of osteopathic manipulative treatment techniques for chronic low‐back pain |
| Participants |
Patients: out‐patients with chronic low‐back pain
Baseline comparability: yes |
| Interventions |
Placebo: simulated osteopathic manipulative treatment techniques
Untreated: no simulated osteopathic manipulative treatment techniques
Experimental: osteopathic manipulative treatment techniques
(Co‐intervention: 'usual or other low back care') |
| Outcomes |
Back pain (VAS)
SF‐36 health survey (physical functioning subscale)
SF‐36 health survey (all subscales)
Roland‐Morris disability questionnaire
Lost work or school days
Satisfaction with back care |
| Notes |
We selected back pain as the relevant outcome (and not the SF‐36 which was the basis for the power calculation), because also back pain was described as a 'main outcome', and because pain (and not quality of life) is mentioned in the aims section and the title. We extracted pain data (at six months) from Figure 3 |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Adequate sequence generation? |
Unclear risk |
NS |
| Allocation concealment? |
Low risk |
'sequentially sealed envelopes' |
| Blinding?
Treatment provider |
High risk |
Not described as double‐blind (placebo/manipulation) |
| Blinding?
Outcome assessor |
Unclear risk |
Not relevant as patient reported outcome |
| Incomplete outcome data addressed?
All outcomes |
High risk |
Drop‐out > 15% or NS |
| Free of selective reporting? |
Unclear risk |
No protocol available |
| Free of other bias? |
Low risk |
|
| No signs of variance inequality or skewness? |
High risk |
Either variance inequality (F‐test statistically significant) or skewness (1.64 standard deviations exceeds the mean) |
| Trial size > 49? |
High risk |
N = 34 |
| Clearly concealed allocation + trial size > 49 + drop‐out max 15% |
High risk |
Trial size < 49 |
