an immediate risk of dying during or shortly after surgery. Accordingly, users of the reports of surgical trials should look for information on immediate and early mortality (typically higher in the surgical group) in addition to longer-term results. If the article's results are generalizable to your patient and its outcomes are important, the next question concerns whether the probable treatment benefits are worth the effort that you and your patient must put into the enterprise. A 25% reduction in the risk of death may sound quite impressive, but its impact on your patient and practice may nevertheless be minimal. This notion is illustrated using a concept called "number needed to treat" (NNT) [30] . The impact of a treatment is related not only to its relative risk reduction, but also to the risk of the adverse outcome it is designed to prevent. Beta blockers reduce the risk of death following myocardial infarction by approximately 25%, and this RRR is consistent across subgroups, including those at higher and lower "baseline" risk of recurrence and death when they are untreated. Table 3 considers two patients with recent myocardial infarctions. Table 3: Two men with contrasting prognoses following myocardial infarction If the risk of death at one year without therapy (baseline risk) is: X First, consider a 40 year old man with a small infarct, normal exercise capacity, and no sign of ventricular arrhythmia who is willing to stop smoking, begin exercising, lose weight, and take aspirin daily. This individual's risk of death