Abstract
PURPOSE: Knee osteoarthritis (KOA) is a common degenerative joint disease that severely affects quality of life. Gamidaeganghwal-tang (GMDGHT), a traditional Korean herbal medicine, has been widely used to treat joint pain and stiffness. However, robust clinical evidence for its efficacy and safety is lacking. This trial protocol aims to evaluate the efficacy, safety, and cost-effectiveness of GMDGHT compared to a placebo in patients with degenerative KOA. TRIAL DESIGN AND METHODS: This protocol describes a multicenter, randomized, double-blind, placebo-controlled, parallel-group clinical trial. A total of 160 participants (80 per group) will be recruited from four Korean medicine hospitals. Eligible participants aged 40-70 years must have radiographic KOA (Kellgren-Lawrence grades I-III) and a Korean Western Ontario and McMaster Universities Osteoarthritis Index (K-WOMAC) score ≥30. Participants will be randomly assigned 1:1 to receive either GMDGHT or placebo granules (10 g, orally, three times daily) for 12 weeks, followed by a 12-week observation period. Assessments will be conducted at baseline and at weeks 4, 8, 12, and 24. The primary outcome will be the change in total K-WOMAC score from baseline to week 12. Secondary outcomes include pain intensity (100-mm visual analog scale), quality of life using the EuroQol 5-dimension 5-level (EQ-5D-5L), patient satisfaction, rescue medication use, and cost-effectiveness from societal and healthcare perspectives. Safety will be monitored through adverse events and laboratory findings. DISCUSSION: This trial will rigorously evaluate the efficacy, safety, and cost-effectiveness of GMDGHT for KOA. Despite efforts to maintain blinding with identically packaged placebo granules, subtle differences in taste or texture may challenge complete participant blinding. Restrictions on concomitant therapies may also influence adherence. Nonetheless, this study is designed to minimize potential bias and generate reliable clinical evidence on GMDGHT's role as a complementary or alternative therapeutic option for KOA. TRIAL REGISTRATION NUMBER: KCT0008486 (Clinical Research Information Service of the Republic of Korea), registered on 01 June 2023. IND APPROVAL NUMBER: 101414 (Approved by the Ministry of Food and Drug Safety, Republic of Korea) on April 19, 2023.