Randomized Controlled Trials of Acupuncture for Neck Pain: Systematic Review and Meta-Analysis

Objectives: The objectives of this study were to assess the effectiveness and efficacy of acupuncture in the treatment of neck pain. Data sources: The following computerized databases were searched from their inception to January 2008: MEDLINE (PubMed), ALT HEALTH WATCH (EBSCO), CINAHL, and Cochrane Central. Review methods: Systematic review and meta-analysis were conducted on randomized controlled trials of acupuncture for neck pain. Two (2) reviewers independently extracted data concerning study characteristics, methods, and outcomes, as well as performed quality assessment based on the adapted criteria of Jadad. Results: Fourteen (14) studies were included in this review. Meta-analysis was performed only in the absence of statistically significant heterogeneity among studies that were selected for testing a specific clinical hypothesis. While only a single meta-analysis was done in previous reviews, this review performed nine meta-analyses addressing different clinical issues. Seven out of nine meta-analyses yielded positive results. In particular, the meta-analysis based on the primary outcome of short-term pain reduction found that acupuncture was more effective than the control in the treatment of neck pain, with a pooled standardized mean difference (SMD) of -0.45 (95% confidence interval [CI], -0.69 to -0.22). Moreover, the meta-analysis with a pooled SMD of -0.53 (95% CI, -0.94 to -0.11) showed that acupuncture was significantly more effective than sham acupuncture for pain relief. However, there was limited evidence based on the qualitative analysis of the trial data to support the above conclusions. We provided a detailed analysis on the issue of heterogeneity of the studies involved in meta-analysis and examined the consistencies and inconsistencies among the present review and two other reviews conducted previously. Conclusions: The quantitative meta-analysis conducted in this review confirmed the short-term effectiveness and efficacy of acupuncture in the treatment of neck pain. Further studies that address the long-term efficacy of acupuncture for neck pain are warranted.