Efficacy of Rebox Electrotherapy in Pain Management: A Randomized Double-Blind Sham-Controlled Crossover Trial

Rebox therapy is a form of noninvasive transcutaneous electrotherapy, which delivers microcurrent kilohertz-frequency pulses in multiple points over the target area. Despite decades of use in pain management, clinical evidence supporting Rebox remains inconclusive, with a lack of rigorous sham-controlled trials. This study aimed to evaluate its analgesic effect in a single-center, randomized, double-blind, sham-controlled crossover trial. The study included consecutive patients with non-cancer nociceptive pain with average pain intensity ≥ 4 on a numerical rating scale (NRS), and pain duration of 2-12 weeks (de novo or acutely exacerbated chronic pain). Patients were randomized (1:1) into two arms based on the sequence of stimulation periods. Each period consisted of eight sessions of either Rebox or sham treatment, administered every other working day, with a 1-week washout period. The primary outcome was the difference in the reduction of pain intensity (average and worst pain in the last 24 h) following active versus sham stimulation. Seventy-one patients completed the study, with musculoskeletal back pain being the most common indication (n = 60). Compared to the sham, Rebox significantly reduced both average pain (NRS difference: 2.2, 95% CI 0.8-3.6, Cohen's d = 0.75, p = 0.002) and worst pain (NRS difference: 2.3, 95% CI 1.2-3.5, Cohen's d = 0.91, p < 0.001). A significant placebo analgesic effect was observed only in the sham-first arm. The treatment was well tolerated, with only minor and transient side effects. Rebox demonstrated a significant analgesic effect compared to the sham. The treatment was safe and well tolerated. These findings support integrating Rebox into clinical pain management, warranting further investigation in larger trials.