Acupuncture Versus Sham-acupuncture: A Meta-analysis on Evidence for Non-immediate Effects of Acupuncture in Musculoskeletal Disorders

OBJECTIVE: Acupuncture is a common modality in the therapy of musculoskeletal disorders. The evidence for acupuncture has already been examined frequently but a clear synthesis of previous research is currently lacking. This meta-analysis aims to summarize the evidence for non-immediate effects of acupuncture on pain, functionality and quality of life (QOL) in patients with musculoskeletal disorders, when compared to sham acupuncture. METHODS: Search results from Pubmed and Web of science were brought together. All screening procedures were executed twice by two independent researchers. The pooled standardized mean difference (SMD) with its confidence interval (CI) were estimated at follow-up less than one month, one to three months, three to six months and more than six months. RESULTS: For pain, the SMD equalled respectively -1.24 (CI -1.98 to -0.49), -1.06 (CI -1.61 to -0.51), -2.34 (CI -3.46 to -1.21) and -0.12 (CI -0.36 to 0.11). For functionality, the pooled SMD equalled -0.63 (CI -1.16 to -0.10), -0.62 (CI -1.33 to 0.08), -0.20 (CI -2.10 to 1.70), and -0.13 (-0.46 to 0.19). In the area of QOL, pooled SMD of respectively -0.98 (CI -2.37 to 0.41), -0.64 (CI -1.42 to 0.14), -0.70 (CI -1.43 to 0.03) and -0.59 (CI -0.80 to -0.38) were obtained. DISCUSSION: A significant difference in therapy effect, favouring acupuncture, was found for pain at less than one month, one to three months and three to six months, as well as on functionality at less than one month. Absence of a significant difference between both modalities was decided upon in all other outcome categories.