The Effectiveness of Auricular Acupressure on Chronic Musculoskeletal Pain: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Objectives: To assess the effectiveness of auricular acupressure (AA) in managing pain and disability in individuals with chronic musculoskeletal pain.Materials and Methods: A systematic search on six electronic databases was performed from their inception to May 7, 2023, to identified relevant randomized controlled trials (RCTs). Two independent reviewers screened the abstracts and full texts, extracted data, and assessed risk of bias using RoB 2. The primary outcomes were pain intensity and disability. The secondary outcomes were pain pressure thresholds, pain catastrophizing level, and fear avoidance beliefs. A random-effects model was used for meta-analyses. The certainty of evidence was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation. Sensitivity analyses were conducted after removing low-quality papers.Results: Of 633 identified records, six studies involving 496 participants were included. All included studies compared the effectiveness of AA with sham controls in treating various chronic musculoskeletal pain. Four meta-analyses were conducted to compare the effectiveness of AA with sham controls. Low-quality evidence supported that AA had a large effect size on postintervention subjective pain reduction (standardized mean difference [SMD] = -0.95; 95% confidence interval [CI]: -1.36 to -0.54; p = 0.00; I2 = 52.61%); moderate-quality evidence substantiated that AA had a large effect size on enhancing postintervention pressure pain threshold (SMD = -0.55; 95% CI: -0.88 to -0.23; p = 0.00; I2 = 0%). There was low-quality evidence that AA had a large effect on reducing postintervention disability (SMD = -0.68; 95% CI: -1.24 to -0.12; p = 0.02; I2 = 51.33%). Our sensitivity analysis reaffirmed the same conclusion regarding pain reduction immediately after the intervention. Fourteen participants reported minimal adverse events, including soreness, tenderness, irritation, and redness, which disappeared within 1-7 days.Discussion: Our systematic review revealed that AA significantly improved pain, pressure pain thresholds, and disability in individuals with various chronic musculoskeletal pain conditions immediately post-treatment compared with sham treatment. Given the paucity of studies and inconsistent protocols, future RCTs are warranted to evaluate the effectiveness of AA in people with chronic musculoskeletal pain at a longer follow-up with detailed protocols, which allows researchers and clinicians to optimize AA intervention.Conclusion: AA has immediate post-treatment benefits for chronic musculoskeletal pain, whereas its effects at the 1- or 6-month follow-up remain uncertain.