[Surrogate end points]

Abstract

In order to evaluate the efficacy of a treatment, "minor" end points (the reduction in serum cholesterol, blood pressure, serum creatinine) that have a pathophysiological or statistical relationship with the true end points (reduction in mortality, incidence of myocardial infarction, or surgical procedures) are often adopted. They are called surrogate end points because they are used instead of true end points. In cardiology the results of clinical trials with clofibrate, milrinone, flecainide and more recently with doxazosine have demonstrated that the reduction of a surrogate end point does not correspond to the reduction of mortality. To define a treatment for a patient, clinicians should distinguish surrogate from true end points choosing evidence-based treatments and avoiding those that are supported only by pathophysiological assumptions.