A major tool was the component scoring system for the Structured Interview to determine which of the many attributes comprising the multidimensional Type A behavior pattern were actually associated with coronary heart disease. Component scoring had demonstrated that some components had consistent associations with coronary heart disease, even when the global Type A behavior pattern showed no relationship. Component analysis of the Type A behavior pattern in MRFIT revealed that of all the attributes assessed, only Potential for Hostility was significantly related to incidence of coronary heart disease. Several other studies were conducted under this project. Tape-recorded Structured Interviews from the Western Collaborative Group Study were reanalyzed to assess the relationship between components of Type A behavior and incidence of coronary heart disease. Rescoring was completed on Structured Interviews of over 1,000 subjects who had undergone stress testing while blood pressure and heart rate were recorded. An analysis was also conducted on the influence of cigarette smoking and situational stress on cardiovascular response in young male subjects.