Individuals with Type A behavior are characterized as hard driving, competitive, and time urgent; when asked questions they are quick to answer with emphatic speech; they perceive themselves to be striving and competing and are prone to hostility. This core of behaviors is presumed to be on a continuum of intensity with well-developed Type A's at the upper end and well-developed Type B's at the lower end. Epidemiological studies have shown Type A's to have a higher prevalence and incidence of various forms of coronary heart disease than Type B's. The Structured Interview is a method of measuring Type A behavior in which a series of questions are administered about the individual's characteristic responses to situations relevant to the Type A behavior pattern, such as reaction to delay and reported frequency of anger. The Interview is delivered in challenging style designed to elicit Type A characteristics.