Importance: Chronic low back pain has high societal and personal impact but remains challenging to treat. Electroacupuncture has demonstrated superior analgesia compared with placebo in animal studies but has not been extensively studied in human chronic pain conditions.
Objective: To evaluate the treatment effect of real electroacupuncture vs placebo in pain and disability among adults with chronic low back pain and to explore psychophysical, affective, and demographic factors associated with response to electroacupuncture vs placebo in treating chronic low back pain.
Design, setting, and participants: This double-blind randomized clinical trial was conducted between August 2, 2016, and December 18, 2018, at a single center in Stanford, California. Primary outcomes were collected at approximately 2 weeks before and after intervention. Participants included English-speaking adults with at least 6 months of chronic low back pain, pain intensity of at least 4 on a scale of 0 to 10, and no radiculopathy. Data analyses for this intent-to-treat study were conducted from June 2019 to June 2020.
Interventions: Twelve sessions of real or placebo (sham) electroacupuncture administered twice a week over 6 weeks.
Main outcomes and measures: The main outcome was change in pain severity from baseline to 2 weeks after completion of treatment, measured by the National Institutes of Health PROMIS pain intensity scale. A secondary outcome was change in the Roland Morris Disability Questionnaire (RMDQ). Baseline factors potentially associated with these outcomes included psychophysical testing (ie, thermal temporal summation, conditioned pain modulation, pressure pain threshold), participant's self-report (ie, widespread pain, coping strategies, expectations, self-efficacy, and pain catastrophizing), and demographic characteristics (eg, age, sex, and race).
Results: A total of 121 adults were recruited to the study, among whom 59 participants (mean [SD] age, 46.8 [11.9] years; 36 [61.0%] women) were randomized to real electroacupuncture and 62 participants (mean [SD] age, 45.6 [12.8] years; 33 [53.2%] women) were randomized to sham electroacupuncture. At baseline, the mean (SD) PROMIS T-score was 50.49 (3.36) in the real electroacupuncture group and 51.71 (4.70) in the sham acupuncture group, and the mean (SD) RMDQ score was 10.16 (4.76) in the real electroacupuncture group and 10.03 (5.45) in the sham acupuncture group. After adjusting for baseline pain scores, there was no statistically significant difference between groups in change in T-scores 2 weeks after completion of treatment (real electroacupuncture: -4.33; 95% CI, -6.36 to -2.30; sham acupuncture: -2.90; 95% CI, -4.85 to -0.95; difference: -2.09; 95% CI, -4.27 to 0.09; P = .06). After adjusting for baseline RMDQ, there was a significantly greater reduction in RMDQ in the real electroacupuncture group (-2.77; 95% CI, -4.11 to -1.43) compared with the sham electroacupuncture group (-0.67; 95% CI, -1.88 to 0.55; difference: -2.11; 95% CI, -3.75 to -0.47; P = .01). Within the real electroacupuncture group, effective coping at baseline was associated with greater RMDQ reduction (r = -0.32; 95% CI, -0.54 to -0.05; P = .02), and White race was associated with worse outcomes in PROMIS score (β = 3.791; 95% CI, 0.616 to 6.965; P = .02) and RMDQ (β = 2.878; 95% CI, 0.506 to 5.250; P = .02).
Conclusions and relevance: This randomized clinical trial found no statistically significant difference in change in PROMIS pain score in real electroacupuncture vs sham electroacupuncture. There was a statistically significant treatment effect for the secondary outcome of RMDQ compared with sham electroacupuncture. Effective coping skills and non-White race were associated with response to electroacupuncture.
Trial registration: ClinicalTrials.gov Identifier: NCT02890810.