Efficacy of a Chinese herbal medicine in the treatment for patients with knee osteoarthritis : a randomised, double blind, placebo controlled pilot trial

Introduction: Chinese herbal medicine (CHM) is a popular alternative therapy for osteoarthritis (OA), however the majority of CHM efficacy studies have been methodologically inadequate. This study was the first randomised, double-blind, and placebo-controlled clinical trial of a CHM formula in an Australian OA population. Methods: Eligible participants were randomised to receive either CHM or placebo over 12 weeks, with a one month follow-up. Each subject attended a total of six clinic visits. Study participants and investigators were both blinded to the block randomisation number code until the statistical analyses were completed. The Western Ontario and McMaster Universities Arthritis (WOMAC) Index was used as the primary outcome variable. Safety monitoring was conducted throughout the study. Results: 47 participants were recruited into the study. The study had a 62% power to detect a significant difference in the primary outcome variable. Within-group analyses indicated significant improvements (p< 0.05) in terms of change of the WOMAC indices of pain, physical activity and total score in both groups, but there was no significant difference (p> 0.05) between the groups. The effectiveness of the CHM formula was maintained in the follow-up period but not in the placebo group. Safety data indicated the CHM was safe and well tolerated. Conclusions: There is some limited indication of a therapeutic effect for the CHM. Larger scale studies over a longer time period are required.