To the Editor: In their JAMA Classics commentary, Drs Montori and Guyatt1 discussed the progress made since the introduction of evidence-based medicine (EBM). The integration of best available evidence with clinical expertise and patient values forms the cornerstone of this approach. Unfortunately, clinicians and regulatory authorities often experience pressure to adopt treatment modalities long before the accumulation of supporting data. Of special concern is that individual therapies may have a good evidence base compared with placebo, but there may be little evidence of differences between available therapies.