Arthritis and rheumatism
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Arthritis and rheumatism · Jul 2001
Randomized Controlled Trial Multicenter Study Clinical TrialStratification of flare intensity identifies placebo responders in a treatment efficacy trial of patients with osteoarthritis.
Studies evaluating osteoarthritis treatment often use increased arthritis activity ("flare") as a selection criterion, although no standardized assessments are available to quantify flare intensity and little is known about how this criterion affects treatment comparisons. This study evaluated the reliability of a flare assessment and how pretreatment flare intensity impacts conclusions on treatment efficacy. ⋯ Patients with higher intensity flares may be more likely to report substantial improvement in functional status regardless of treatment. Failure to account for flare intensity in analyses of data from pain trials with flare-based designs may inflate the risk of Type I and Type II errors in the interpretation of study results.