Development of the Core Outcome Set for Herbal Medicine Treatment of Lumbar Disc Herniation (COS‐HM‐LDH) in Korean Medicine Practice

ABSTRACT Background Lumbar disc herniation (LDH) is a common cause of low back pain and disability. Herbal medicine (HM) is increasingly used for LDH in Korean medicine (KM) practice, but evidence synthesis is limited by inconsistent outcome selection and reporting. We aimed to develop a core outcome set (COS) to standardize reporting in HM studies of LDH in KM practice. Methods The study followed the Core Outcome Set‐STAndards for Development (COS‐STAD), with reporting guided by the Core Outcome Set‐STAndards for Reporting (COS‐STAR). Candidate outcomes were identified through a systematic review of Korean (OASIS, ScienceON) and international (PubMed, CENTRAL) databases from inception to December 2024, supplemented by clinical practice guidelines and textbooks. Outcomes were refined into predefined domains and potential effect modifiers (EMs) were identified. A two‐round Delphi survey with experts was conducted, followed by a Delphi survey with KM clinicians to assess feasibility in practice. A structured consensus meeting was held to finalize th