Primary Care

Non-steroidal anti-inflammatory drugs, including cyclo-oxygenase-2 inhibitors, in osteoarthritic knee pain: meta-analysis of randomised placebo controlled trials

BMJ 2004; 329 doi: (Published 02 December 2004) Cite this as: BMJ 2004;329:1317
  1. Jan Magnus Bjordal (jmb{at}, research fellow1,
  2. Anne Elisabeth Ljunggren, professor1,
  3. Atle Klovning, associate professor1,
  4. Lars Slørdal, professor2
  1. 1 Department of Public Health and Primary Health Care, University of Bergen, 5018 Bergen, Norway
  2. 2 Department of Laboratory Medicine, Children's and Women's Health, Norwegian University of Science and Technology, 7489 Trondheim, Norway
  1. Correspondence to: J M Bjordal
  • Accepted 14 September 2004


Objective To estimate the analgesic efficacy of non-steroidal anti-inflammatory drugs (NSAIDs), including selective cyclo-oxygenase-2 inhibitors (coxibs), in patients with osteoarthritis of the knee.

Design Systematic review and meta-analysis of randomised placebo controlled trials.

Studies reviewed 23 trials including 10 845 patients, median age of 62.5 years. 7807 patients received adequate doses of NSAIDs and 3038 received placebo. The mean weighted baseline pain score was 64.2 mm on 100 mm visual analogue scale (VAS), and average duration of symptoms was 8.2 years.

Main outcome measure Change in overall intensity of pain.

Results Methodological quality of trials was acceptable, but 13 trials excluded patients before randomisation if they did not respond to NSAIDs. One trial provided long term data for pain that showed no significant effect of NSAIDs compared with placebo at one to four years. The pooled difference for pain on visual analogue scale in all included trials was 10.1 mm (95% confidence interval 7.4 to 12.8) or 15.6% better than placebo after 2-13 weeks. The results were heterogeneous, and the effect size for pain reduction was 0.32 (0.24 to 0.39) in a random effects model. In 10 trials that did not exclude non-responders to NSAID treatment the results were homogeneous, with an effect size for pain reduction of 0.23 (0.15 to 0.31).

Conclusion NSAIDs can reduce short term pain in osteoarthritis of the knee slightly better than placebo, but the current analysis does not support long term use of NSAIDs for this condition. As serious adverse effects are associated with oral NSAIDs, only limited use can be recommended.


  • Contributors JMB had the original idea and designed the review together with LS. JMB and AK performed the literature search. AEL and JMB assessed methodological trial quality. JMB, LS, and AK analysed the statistical data. AEL, JMB, and LS wrote the report, while AK contributed in layout and proof reading. JMB is the guarantor.

  • Funding None.

  • Competing interests None declared.

  • Ethical approval Not required.

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