NSAIDs reduce osteoarthritic knee pain in the short term; long term effects are unknown

Abstract

What is the analgesic effect of NSAIDs, including coxibs, in patients with knee osteoarthritis? MEDLINE, EMBASE, and The Cochrane Controlled Trials Register (CENTRAL) from 1966 to April 2004. Reference lists from relevant articles were scanned. Relevant studies were also traced by contacting experts. Randomised controlled trials of patients whose knee osteoarthritis had been verified by clinical examination according to the American College of Rheumatology criteria and by X-ray, where the intervention groups had to have received matched placebo drug or adequate NSAID dose and the outcome measure was pain. Methodological quality was assessed according to predefined criteria (Jadad scale). It is not reported if selection and assessment of trials were done by one or more reviewers. Twenty-three trials of moderate or good methodological quality were included. The included patients (n = 10 845) had a median age of 62.5 years, 67.9% were women, and the median duration of symptoms was 8.2 years. Thirteen trials used an additional inclusion criterion by requiring a predefined minimum flare of symptoms when NSAID treatment was discontinued in the pretreatment wash out period. Only one trial reported long term effects on pain but found no significant difference between NSAID and placebo at one, two, three, and four years after start of treatment. For short term effects (2–13 weeks) the pooled effect size in change in pain between the treatment and the placebo groups was 0.32 (95% CI 0.24 to 0.39), comparable to 10.1 mm on visual analogue scale (VAS) (7.4 to 12.8) or 15.6% better than placebo. For the subgroup of 10 trials (n = 4565) that did not require patients to have a minimum flare of symptoms after treatment with NSAIDs was stopped before the trial, the pooled effect size for pain was 0.23 (0.16 to 0.31) or 5.9 mm on VAS (3.8 to 7.9). NSAIDs can reduce short term pain in osteoarthritis of the knee slightly better than placebo. Evidence of long term effects from oral NSAIDs is still lacking.