Corticosteroids in stable chronic obstructive pulmonary disease: reappraisal of efficacy.

Although systemic corticosteroids are widely used in treating stable chronic obstructive pulmonary disease (COPD), the evidence for their efficacy is still disputed. To reappraise this evidence, the authors used a new analytic strategy in which the 14 available randomized clinical trials were evaluated according to a methodologic "review of systems" and an examination of the statistical precision of the outcome results. Although none of the trials satisfied all of the methodologic criteria for both validity and clinical pertinence, the trials finding steroids efficacious were generally better designed and more statistically precise than trials failing to show efficacy. The authors propose a set of five main methodologic guidelines that require a stable baseline state, a crossover design with suitable washout, adequate doses of corticosteroids, pragmatic designs, and comprehensive choices of outcome events. Attention to these guidelines can help improve both design and evaluation for future trials of systemic steroids for stable COPD.