Effectiveness and Safety of Herbal Decoctions for Functional Dyspepsia in Korean Medicine Clinics: A Multicenter Prospective Cohort Study Protocol

Objective: Functional dyspepsia (FD) is frequently treated in Korean Medicine (KM) clinics in South Korea. With the recent inclusion of herbal decoctions (HDs) for FD in the national pilot program for health insurance coverage, the generation of real-world evidence has become an important policy priority. In this study, we aim to evaluate the real-world clinical outcomes and safety of individualized HD-centered KM care in patients with FD in a primary care setting. Methods: This multicenter, prospective, single-arm observational cohort study will enroll 150 participants who meet the Rome IV criteria for FD across 23 KM clinics nationwide. Participants will receive individualized HDs, prescribed at the discretion of the attending physicians, as the primary treatment for 4 weeks. Concomitant KM treatments (e.g., acupuncture, moxibustion, and cupping) are permitted as clinically needed to preserve the pragmatic nature of routine care. The primary outcome is the change in the total symptom score on the Nepean Dyspepsia Index, Korean version (NDI-K), at week 4. Secondary outcomes include the Numeric Rating Scale for overall severity, overall treatment effect, and safety monitoring. Statistical analyses will be performed using mixed models for repeated measures to account for repeated observations and missing data. Discussion: This study will evaluate the pragmatic outcomes of individualized HD-centered KM care in routine clinical practice, thereby supporting the external validity of its findings. The findings are expected to provide foundational real-world data for the national HD pilot program, and these data may serve as a reference for healthcare policies and clinical decision-making. Clinical Trial Registration: Clinical Research Information Service (registration number KCT0010254); registered on 11 February 2025.