Herbal medicine evaluation for reimbursement-based post-stroke sequelae (HERB-PSS): a retrospective analysis using Korean health insurance claim data, 2020–2024

Introduction Stroke is a leading cause of long-term disability, and many patients experience persistent neurological and functional impairments after the acute phase. The Korean government launched a national pilot reimbursement program for herbal decoctions to improve access to Korean Medicine (KM) rehabilitation and generate real-world evidence on its safety and effectiveness. This study aimed to analyze the utilization patterns, clinical outcomes, and safety of herbal medicine (HM) among patients with post-stroke sequelae participating in the pilot program. Methods A retrospective analysis was conducted using nationwide health insurance claims data from the Health Insurance Review and Assessment Service (HIRA). Patients diagnosed with sequelae of cerebrovascular disease (KCD codes I69 or U234) who received reimbursed HM prescriptions between November 2020 and April 2024 were included. Demographic characteristics, prescription patterns, and symptom severity were analyzed. Symptom changes between the first and last visits were assessed using the Wilcoxon signed-rank test, and adverse events (AEs) were identified from newly added diagnostic codes after HM treatment. Results A total of 942 eligible patients were analyzed, with a mean age of 73.2 ± 6.0 years. The majority (57%) initiated KM treatment more than 1 year after stroke onset. The most frequently prescribed formulas were Gamidaebo-tang (23.1%), Mangeum-tang (5.8%), and Gagampalmi-hwan (5.1%). Among 609 patients with paired symptom records, 19.4% showed improvement, 71.9% remained stable, and 8.7% worsened ( p 0.001). AEs occurred in 1.03% (10/962) of patients, predominantly gastrointestinal symptoms such as diarrhea (55.6%). All reported AEs were mild and self-limiting. Conclusion This study provides the first nationwide real-world evidence on the use, effectiveness, and safety of HM for post-stroke sequelae under Korea’s pilot reimbursement program. Individualized herbal decoctions were widely prescribed and generally well tolerated, showing meaningful symptom stabilization in chronic stroke care. These findings support the feasibility and clinical safety of reimbursed HM and highlight the need for prospective studies to evaluate long-term outcomes, safety, and cost-effectiveness under the expanded second-phase program.