[Decision making in cardiology: methodology].
This article reviews the methods employed in usual clinical thinking for making decisions, the problems and limitations inherent in them and claims that a more frequent utilization of the so called "Evidence Based Medicine" methods is a more valid and efficient alternative for medical decision making. We also describe the theoretical basis and strategies used in the medical decision process; the specific concepts and basic components for building decision trees are also shown. Finally, a real case is presented and approached step by step: the statement of the decision problem, its possible alternatives, the allocation of probabilities to each outcome based on the best available evidence, and the calculations of the expected values (projected usefulness, cost-effectiveness) and sensitivity analysis by means of specific software for making decisions.