Short-term placebo response in trials of patients with symptomatic osteoarthritis: differences between hip and knee

摘要

Background: In placebo-controlled RCT of symptomatic treatment in osteoarthritis (OA) the extent of pain reduction is heterogeneous, the pooled effect size rather small. Pain reduction is typically higher in knee than in hip trials. The recommended trial duration is 3 months, but in knee OA the best treatment effect vs placebo is observed at 2 weeks. We hypothesized that the placebo response differs in knee vs hip OA.