| Methods |
Design: three group parallel trial
Purpose: examine the effect of chiropractic spinal manipulation on acute low back pain |
| Participants |
Patients: out‐patients with acute low back pain
Baseline comparability: no, stratified for sex |
| Interventions |
Placebo: light physical touch by investigator at L4/L5‐S1 region
Untreated: no touch or manipulation
Experimental: low amplitude high velocity manipulation of L4/L5‐S1 region
(Co‐intervention: no) |
| Outcomes |
Pain (5‐point NRS)
Plasma B‐endorphin concentration |
| Notes |
|
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Adequate sequence generation? |
Low risk |
'table of random numbers' |
| Allocation concealment? |
Unclear risk |
NS |
| 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 |
Low risk |
Drop‐out < 15% |
| Free of selective reporting? |
Unclear risk |
No protocol available |
| Free of other bias? |
Low risk |
|
| No signs of variance inequality or skewness? |
Low risk |
No variance inequality (F‐test not statistically significant) and no skewness (1.64 standard deviations does not exceed the mean) |
| Trial size > 49? |
High risk |
N = 12 |
| Clearly concealed allocation + trial size > 49 + drop‐out max 15% |
High risk |
Trial size < 49 |
