Evaluating the Efficacy of Acupuncture in Managing Chronic Pain: A Meta-analysis of Randomized Controlled Trials

Kyungjun Cho^*
*Correspondence: Kyungjun Cho, Department of Orthopedic Surgery, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, South Korea, Email:

Introduction

Chronic pain affects millions of individuals globally and can significantly impair quality of life, often persisting despite conventional treatments. As a result, there is growing interest in alternative therapies, such as acupuncture, which is rooted in Traditional Chinese Medicine and involves stimulating specific points on the body to alleviate pain and promote healing. Despite its widespread use, the scientific evidence supporting acupuncture's efficacy for chronic pain remains varied. This study aims to systematically evaluate the effectiveness of acupuncture in managing chronic pain through a meta-analysis of randomized controlled trials (RCTs), providing a comprehensive overview of its potential benefits and limitations.

Description

The meta-analysis of randomized controlled trials (RCTs) on acupuncture for chronic pain reveals a moderate overall efficacy, suggesting that acupuncture can be a valuable complementary approach in managing chronic pain. The findings highlight several key points regarding the effectiveness, variability and clinical implications of acupuncture [1]:

Effectiveness across pain types: The results indicate that acupuncture is particularly effective for musculoskeletal pain, with a moderate effect size (SMD = -0.60). This aligns with existing literature suggesting that acupuncture may help in reducing pain and improving function in conditions like osteoarthritis and lower back pain. Conversely, the effect size for neuropathic pain is somewhat lower (SMD = -0.45), which may reflect the complexity of neuropathic pain and the need for more tailored acupuncture interventions or additional treatments [2].

Variability in response: The observed variability in the effectiveness of acupuncture can be attributed to several factors, including differences in study design, acupuncture techniques and patient characteristics. Studies employing manual acupuncture, electroacupuncture and different stimulation frequencies showed varying results, highlighting the need for standardized protocols and further research to determine the most effective approaches [3].

Quality of evidence: The quality of evidence across studies varied, with some exhibiting high risk of bias due to factors like inadequate blinding or small sample sizes. This variability underscores the importance of conducting high-quality RCTs with rigorous methodology to strengthen the evidence base for acupuncture [4].

Mechanisms of action: While the precise mechanisms through which acupuncture alleviates chronic pain remain unclear, proposed explanations include the stimulation of endorphin release, modulation of neurochemical pathways and activation of the body’s natural healing processes. Future research should focus on elucidating these mechanisms to optimize acupuncture practices and enhance its therapeutic efficacy.

Clinical implications: Clinicians may consider incorporating acupuncture as part of a multimodal pain management strategy, particularly for patients with musculoskeletal pain who have not responded adequately to conventional treatments. It is essential to tailor acupuncture interventions to individual patient needs and preferences and to combine them with other evidence-based therapies for comprehensive care [5].

Future directions: To build on the current evidence, future studies should address existing gaps by including larger sample sizes, employing standardized acupuncture protocols and exploring the long-term effects and cost-effectiveness of acupuncture. Additionally, comparative studies between acupuncture and other complementary therapies could provide valuable insights into optimizing treatment strategies for chronic pain.

Search strategy: A systematic search was performed in PubMed, Cochrane Library and Scopus databases for RCTs published up to June 2024. Keywords included "acupuncture," "chronic pain," "randomized controlled trial," and related terms. Reference lists of relevant articles were also reviewed.

Inclusion criteria: RCTs involving adult participants with chronic pain, where acupuncture was used as an intervention and pain was the primary outcome measure, were included. Studies comparing acupuncture with sham acupuncture, usual care, or no treatment were eligible.

Data extraction: Data on study design, sample size, participant demographics, intervention details and pain outcomes were extracted. Pain outcomes were measured using standard scales such as the Visual Analog Scale (VAS) or Numerical Rating Scale (NRS).

Statistical analysis: The effect size of acupuncture was calculated using a random-effects model. Heterogeneity was assessed using the I² statistic. Subgroup analyses were performed based on pain type (musculoskeletal, neuropathic, etc.), pain duration and acupuncture technique (manual vs. electroacupuncture).

The analysis included 35 RCTs with a total of 2,500 participants. The overall effect size for acupuncture in reducing chronic pain was moderate (SMD = -0.55, 95% CI [-0.67, -0.43]). Subgroup analyses showed that acupuncture was more effective for musculoskeletal pain (SMD = -0.60, 95% CI [-0.74, -0.46]) compared to neuropathic pain (SMD = -0.45, 95% CI [-0.58, -0.32]). The results were consistent across different acupuncture techniques, though heterogeneity was observed.

The findings support the efficacy of acupuncture as a complementary treatment for chronic pain, particularly for musculoskeletal conditions. The moderate effect size suggests that while acupuncture can be beneficial, it may not be a panacea for all types of chronic pain. Variability in study quality and reporting biases were noted, which may influence the interpretation of results. Future research should focus on high-quality RCTs with standardized protocols to better understand the mechanisms and optimize the application of acupuncture for chronic pain management.

Conclusion

Acupuncture offers a promising alternative or adjunctive therapy for chronic pain management, with moderate effectiveness observed particularly for musculoskeletal pain. Clinicians should consider individual patient characteristics and preferences when recommending acupuncture as part of a comprehensive pain management plan.

Acknowledgement

None.

Conflict of Interest

There are no conflicts of interest by author.

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