A systematic review of randomized controlled trials of pharmacological therapy in osteoarthritis of the knee, with an emphasis on trial methodology

Abstract

We systematically reviewed randomized controlled trials (RCTs) of pharmacological therapy in knee osteoarthritis (OA), published between 1966 and August 1994. RCTs were identified by MEDLINE, supplemented by a manual search of reference lists. Qualitative assessment of RCTs was performed using Gotzsche's method; design and analysis features were rated on a scale of 0 (worst) to 8 (best). Heller et al's method was used to compare efficacy of nonsteroidal antiinflammatory drugs (NSAIDs) in comparative trials. A total of 80 RCTs were analyzed (45 involved NSAIDs, 3 analgesics, 5 intraarticular [IA] steroids, 9 biological agents, including IA hyaluronic acid, and 18 mixed modalities, including topical capsaicin). The median design and analysis scores for all 80 RCTs were 2 and 5, respectively. NSAIDs were superior to placebo in all short-term trials, but in the 32 comparative NSAID trials, only five (16%) found significant differences in efficacy. Heller et al's method identified differences in 14 NSAID comparisons; etodolac (600 mg/day) was superior in five of its nine comparisons. Indomethacin and aspirin were the most toxic NSAIDs. IA steroids were superior to placebo in short-term efficacy (< 1 month). Biological agents were superior to placebo and generally well tolerated over a mean follow-up of 48 weeks. Acetaminophen was superior to placebo and was comparably efficacious to low-dose naproxen and ibuprofen (< 2,400 mg/day). The data support the use of acetaminophen, topical capsaicin, IA steroids, IA hyaluronic acid, and NSAIDs in the treatment of patients with knee OA.