Electro-Acupuncture for the Treatment of Chronic Low Back Pain: Effectiveness and Prediction

Chronic low back pain (CLBP) affects >10% of the population and is often resistant to treatments. Evidence suggests that CLBP may involve central sensi-tization, whereas electro-acupuncture (EA) might relieve pain by reducing central sensitization. We aim to 1) test the effectiveness of EA in treating CLBP in a clinical trial and 2) predict treatment response using markers related to central sensitization using quantitative sensory testing (QST). Methods: Design: This institutional review board-approved study is a randomized, placebo-controlled, clinical trial. Population and Recruitment: Adult men and women with CLBP for more than six months via clinic (Stanford Pain Management) and community (Bay Area) outreach. Intervention: Verum or sham EA twice per week for six consecutive weeks. Assessment: The primary outcome is change in pain intensity, measured by the National Institutes of Health Patient-Reported Outcome Measurement Information System (PROMIS) Pain Intensity Instrument administered at the pre- and post-treatment visits. QST: Temporal summation, conditioned pain modulation, pressure pain threshold and tolerance, thermal thresholds. Additional Measures: Other PROMIS instruments and questionnaires (pain catastrophizing, self-efficacy, expectancy). Power/Analytical Plan: One hundred participants are needed to detect a moderate association (r = 0.4) between temporal summation and pain reduction with 80% power. We will perform repeated-measures analysis of variance to assess for effectiveness and use a mixed-effects model to assess for moderators and build a prediction model. Interim Results: Eighty-five participants have completed the study. A sneak peak of de-identified data showed greater pain reduction in the verum compared with the sham arm, but not statistically significantly so. Conclusion: Interim results show a promising trend of clinical response to verum EA. Further analysis will be carried out once the study is completed.