Herbal decoction and lumbar spine surgery in patients with lumbar disc herniation: a real-world study using linked electronic health records and claims data.

Introduction: Lumbar disc herniation (LDH) is a major cause of low back pain and may require surgical intervention when conservative or non-surgical treatment fails. In Korea, herbal medicine is commonly used as part of non-surgical care; however, its long-term effect on the risk of lumbar surgery has been difficult to assess because herbal decoctions have historically not been recorded in national insurance claims data. Methods: We conducted a retrospective cohort study by linking electronic health records (EHRs) from four Korean medical hospitals with National Health Insurance claims data. Patients newly diagnosed with LDH (ICD-10 M51) between 2016 and 2017 were included. The index date was defined as 1 year after the first hospital visit, and patients were followed until 31 July 2021. Exposure was defined as receiving herbal decoction for ≥30 days versus <30 days during the 1-year period between the entry date and index date. Patients with red-flag conditions or those who underwent lumbar surgery before the index date were excluded from the study. Propensity score matching (1:1) was performed using age, sex, insurance type, Charlson Comorbidity Index, and baseline leg pain numeric rating scale. Lumbar surgery was identified using procedure codes for discectomy, laminectomy, or spinal fusion. Kaplan-Meier analysis and Cox proportional hazards models were used to estimate the association between herbal decoction use and surgery. Results: Among 6,669 eligible patients, 2,504 received herbal decoction for ≥30 days. After propensity score matching, 2,473 patients remained in each group, with good balance across baseline covariates (standardized mean differences <0.1). The ≥30-day group showed a significantly lower cumulative incidence of lumbar surgery compared with the <30-day group (2.63% vs. 3.64%; log-rank p = 0.033). Across sequential Cox regression models, longer herbal decoction use was consistently associated with a reduced risk of lumbar surgery, hazard ratio (HR) 0.71 (95% CI 0.51-0.97). Discussion: In this real-world study linking EHR and claims data, herbal decoction use for ≥30 days was associated with a lower risk of subsequent lumbar spine surgery in patients with LDH. These findings suggest that herbal medicine may be an effective non-surgical treatment option and warrant confirmation in prospective and randomized studies.