Assessing the evidence of effectiveness of acupuncture for stroke rehabilitation: stepped assessment of likelihood of bias

Objective: To investigate the effects of known potential sources of bias on whether acupuncture is beneficial in treating stroke. Data sources: Cochrane Library, MEDLINE, EMBASE, PubMed and reference lists of previous reviews were used to seek randomised controlled trials. There were seven randomised trials that met the inclusion criteria. Methods: Pooling of outcomes was known to be unlikely. Trials were judged by the authors and by us as being positive (acupuncture was helpful) or negative (no benefit could be shown). The effect of trial quality, validity and origin were examined to investigate whether these affected the overall outcome. The overall outcome is there evidence of a benefit and is the size of that benefit worthwhile? was examined from the perspective of the highest quality trials. Results: Our conclusion was that two studies had a positive result and five a negative. The three observer blind trials we judged to be negative. The single trial with a quality score of three was negative. The two trials with a validity score of nine or more we judged to be negative. Two of the three European studies we judged to be negative. Sensitivity analyses based on blinding, reporting quality, validity score and country of origin all showed a higher proportion of positive results for poor quality trials than for those of higher quality. Conclusion: Sensitivity analysis for known sources of bias is important where “vote-counting” replaces data pooling. There were no high quality trials of acupuncture for stroke that showed that it was beneficial.