Prediction of Quality of Life by Type D Personality and Illness Perception Factors in Patients With Coronary Artery Disease: A Structural Equation Model

Background: coronary artery disease (cad) is a common cause of death and disability, with the mortality incidence of 167 per 100,000 people. the known physical cause of coronary heart disease (chd) can predict only 50% of chd incidence. recently, health psychologists pay attention to the key role of nonbiological factors such as psychological factors in chd. objectives: the aim of this study was to examine the direct and indirect relationships between type d personality and quality of life in chd patients and create a conceptual model. patients and methods: in this cross- sectional study, 99 cad patients were finally selected from the patients referred to the angiography unit of mostafa- khomeini hospital in tehran, iran, from april to june 2012. the questionnaires used to gather data were type d personality scale, quality of life scale and illness perception scale. to design the model, we used analysis of moment structures (amos) software because the suggested model was a kind of structural equation models. results: ninety-nine chd patients, with the mean age of 59.7 years (age range, 20 - 86) were studied and 58.8% of them were males. cronbach’s alpha for quality of life and type d personality questionnaires were calculated 0.93 and 0.81, respectively. forty-eight significant parameters estimated in the model that is fitted with the chi-square = 67.905, degrees of freedom = 57 and p-value = 0.153. the type d personality was related to quality of life in patients with chd directly or indirectly by a mediator of the perception of illness. conclusions: diagnosing type d personality and knowing about the effect of these perceptions can help physician to identify patients with prone personality and prevent them from the disease by changing their lifestyle.