1. 2022;25;E931-E939Efficacy of Scrambler Therapy for Management of Chronic Pain: A Meta-Analysis of Randomized Controlled Trials
   Meta-Analysis
   Jangho Hur, MD, PhD, Seung-Kwon Myung, MD, PhD, Yehun Jin, MD, and Daehyun Kim, MD, PhD.

BACKGROUND: Although several randomized controlled trials (RCTs) have reported the efficacy of scrambler therapy (ST) for the management of chronic pain, those findings remain inconsistent.

OBJECTIVES: This meta-analysis aimed to investigate the efficacy of ST for the management of chronic pain.

STUDY DESIGN: A meta-analysis of RCTs.

METHODS: We searched core databases including PubMed, EMBASE, and the Cochrane library for RCTs in October 2021. Standardized mean differences (SMDs) with 95% confidence intervals (CIs) for pain reduction were calculated using a random-effects model meta-analysis.

RESULTS: Out of 348 studies, a total of 7 RCTs (n = 287 patients) that met the inclusion criteria were included in the final analysis. Overall, ST marginally decreased pain scores after the end of the treatment compared with the control group, with substantial heterogeneity (SMD, -0.85; 95% CI, -1.66 to -0.03; I2 = 89.5%, n = 7). A subgroup meta-analysis found that the use of ST significantly reduced analgesic consumption compared to the control group (SMD, -0.54; 95% CI, -0.93 to -0.14; I2 = 0.0%; n = 2). However, no significant efficacy was observed in the subgroup meta-analyses by methodological quality, type of diseases causing pain, and follow-up period.

LIMITATIONS: The included trials have a small sample size and low methodological quality.

CONCLUSIONS: ST seems to be effective in the management of patients with chronic pain. However, further, large RCTs are warranted to confirm our findings.

KEY WORDS: Scrambler therapy, Calmare therapy, chronic pain, meta-analysis, randomized controlled trials