Primary prevention of heart disease and stroke: a simplified approach to estimating risk of events and making drug treatment decisions.

Long-term population-based studies have identified and quantified risk factors for cardiovascular and cerebrovascular (CCV) events. In addition, a number of well-designed clinical trials have shown that various drug therapies that reduce these factors decrease the risk of some CCV events. In the practice of evidence-based medicine, data from clinical trials should inform treatment decisions. The clinician and patient, however, are faced with the difficult task of assessing the patient's particular risk and likelihood of benefit on the basis of the results of large, randomized trials. To assist clinicians and their patients in arriving at treatment decisions, the authors provide simple nomograms for estimating the risk of a CCV event for an individual patient and suggest an approach to estimating the potential benefit of drug therapy for primary prevention.