Types of control in acupuncture clinical trials might affect the conclusion of the trials

Abstract

Objective: To develop acupuncture research guideline, the association of types of control in acupuncture clinical trials and conclusions was investigated. Design: Published RCTs of acupuncture within 10 years were retrieved from electronic databases (Medline, AMED, Cochrane libraries, EMBASE, PsycINFO and CAB Abstracts) by the pre-specified search strategy. Results: 362 studies leading to 394 pairs of acupuncture-control treatment effect comparison (31 studies comprised of 63 intervention-control pairs) were analysed based on the proportion of positive conclusion in different control designs. In trials studying pain condition, we found that treatment effect of acupuncture compared with needle-insertion controls had the lowest tendency to yield positive conclusion (37.8%), compared to non-needle-insertion controls (53.3%). Whereas with non-treatment controls, the highest tendency of positive conclusion was observed (84.3%). In trials studying non-pain condition, we found that treatment effect of acupuncture compared with needle-insertion controls had the highest tendency to yield positive conclusion (68.3%), compared to non-needle-insertion controls (45.7%). Whereas with needle-insertion controls, the higher tendency of positive conclusion was observed (64%). It is likely that superficial needling at non-acupoint did not exert significant therapeutic dose when needle-insertion was used as the sham control group for non-pain conditions. However, superficial needling at non-acupoint was likely to exert therapeutic dose when needle-insertion was used as the sham control groups for pain conditions. Conclusion: We conclude that type of control is likely to affect the conclusion in acupuncture trials. The effectiveness of blinding should be carefully assessed when using superficial needle-insertion control in studying pain conditions. The findings will support developing an acupuncture clinical research methodology guideline.