A meta-analysis investigating the efficacy of NSAIDs vs placebo
in patients with knee OA found a higher effect size (0.32) for studiesthat required a flare of symptoms compared to studies without a flare design (effect size 0.23). Vlad et al. examined differences in
study characteristics among glucosamine trials in OA; they found
consistently higher effect sizes in trials with industry funding (0.47)
vs trials without industry funding (0.05) Furthermore, one
randomized controlled trial (RCT) reported that NSAIDs are superior
in patients with moderate to severe pain, but in patients with
mild intensity pain the differences between NSAIDs and acetaminophen
were negligible14. Bradley et al., reported that higher
baseline pain intensity predicted greater pain relief at follow-up