Comparative effectiveness and safety of herbal medicine therapy for low back pain and radiculopathy caused by lumbar intervertebral disc herniation: a study protocol for a pragmatic randomized controlled trial

BACKGROUND: Low back pain and radiculopathy due to lumbar intervertebral disc herniation are prevalent conditions, significantly impacting quality of life and imposing substantial socioeconomic burdens globally. In Korea, these conditions are frequently managed within traditional Korean medicine clinics, demonstrating high patient preference for such interventions. However, rigorous clinical evidence on the effectiveness, cost-effectiveness, and safety of individual traditional Korean medicine therapies remains insufficient, particularly for older adult populations where surgical risks are elevated. This highlights a critical need for research into conservative treatment approaches, especially pragmatic randomized controlled trials that reflect real-world clinical practice. METHODS: This pragmatic randomized controlled trial will be a two-arm parallel study designed to evaluate the effectiveness and safety of herbal medicine therapy for low back pain and radiculopathy resulting from lumbar intervertebral disc herniation. Seventy-four eligible adult participants, aged 19 years or older, with magnetic resonance imaging or computed tomography confirmed disc bulging or worse and a Numeric Rating Scale score for radiating pain between three and six, will be randomly assigned to either the herbal medicine strategy treatment group or a usual traditional Korean medicine treatment group that excludes herbal medicine. The primary outcomes will be changes in the Numeric Rating Scale for radiating pain and the Oswestry Disability Index at week seven. Secondary outcomes will include various pain, disability, quality of life, and economic evaluation measures assessed at multiple time points up to 26 weeks. Safety will be continuously monitored through adverse event reporting, laboratory tests, and vital signs. Statistical analysis will primarily use intention-to-treat and per-protocol populations, employing linear mixed models for efficacy endpoints and chi-squared or Fisher's exact tests for safety data. Non-inferiority testing will be performed if superiority is not established. CONCLUSION: This pragmatic randomized controlled trial aims to provide robust clinical evidence on the effectiveness, safety, and cost-effectiveness of herbal medicine therapy for lumbar intervertebral disc herniation, particularly in comparison to other traditional Korean medicine interventions. The findings are expected to contribute significantly to developing evidence-based guidelines and optimizing treatment strategies for this prevalent condition, addressing an urgent healthcare need and improving patient outcomes.