Measurement Structure of the Pittsburgh Sleep Quality Index and Its Association with Health Functioning in Patients with Coronary Heart Disease

Research on the underlying structure of sleep measures in patients with coronary heart disease (CHD) is lacking. Existing research on sleep and health outcomes primarily focused on only one dimension of sleep (e.g., sleep duration), leaving other aspects unexamined. To address this gap, this study examined the measurement structure of Pittsburgh Sleep Quality Index (PSQI) and its associations with health-related quality of life among CHD patients. Participants were 167 CHD patients from a cardiac wellness program. Confirmatory factor analysis revealed that the two-factor structure with sleep efficiency and perceived sleep quality best fitted the data. Concurrent validity analyses with structural equation modeling showed that, when considered simultaneously, perceived sleep quality, but not sleep efficiency, was significantly associated with emotional, physical, and social quality of life. Findings demonstrated that the PSQI consists of two moderately correlated factors that are differentially associated with separate health domains in cardiac patients.