Efficacy, Safety, and Economic Feasibility of Dokhwalgisaeng-Tang for Degenerative Knee Osteoarthritis: Protocol for a Multicenter, Randomized, Assessor Blinded, Controlled Trial.

Purpose: Knee osteoarthritis (KOA) is one of the most prevalent degenerative joint diseases worldwide. The herbal decoction, Dokhwalgisaeng-tang (DHGST), has been commonly used in East Asia to treat osteoarthritis. However, there is insufficient evidence to draw clear conclusions concerning its effectiveness and safety for patients with KOA. We aim to determine the efficacy, safety, and economic feasibility of DHGST compared with Celecoxib, an oral COX-2 inhibitor, for patients with degenerative KOA.

Trial Design And Methods: This multicenter, randomized, noninferiority trial, involving 160 participants who will be randomized using block randomization with 1:1 allocation, will compare DHGST and Celecoxib. The total trial period is 24 weeks after random allocation, comprising 12 weeks of treatment and 12 weeks of follow-up. Participants with KOA will be administered 200 mg of DHGST (treatment group) or Celecoxib capsules (control group) for 12 weeks. Efficacy and safety evaluations will be conducted at weeks 0, 4, 8, and 12, and 24. The primary outcome measurement is the Korean Western Ontario McMaster score at week 12. Changes in pain intensity using a 100 mm visual analog scale, changes in quality of life using a EuroQol 5-dimension 5-level self-report survey, and patient satisfaction will also be measured to evaluate effectiveness between the two groups. A trial-based economic feasibility evaluation will be conducted to analyze treatment cost-effectiveness from societal and healthcare system perspectives. Drug safety will be assessed through adverse reactions and laboratory test findings.

Discussion: This trial protocol has the following limitations. Applying a double-dummy design is not possible, as the tablet and granule forms can easily be distinguished visually, and achieving participant blinding is challenging. The trial findings are intended to inform participants, physicians, and other stakeholders in determining whether DHGST could be used as an alternative therapeutic option for KOA.

Trial Registration Number: KCT0008424 (Clinical Research Information Service of the Republic of Korea), registered on 12 May 2023.