Depression and Disease Severity as Predictors of Health-Related Quality of Life in Patients With Chronic Heart Failure-A Structural Equation Modeling Approach

Background: To examine whether depression and heart failure severity are independent predictors of both the physical and psychologic domains of health-related quality of life (HRQoL) in patients with chronic heart failure. Methods and Results: A sample of 206 outpatients with chronic heart failure (mean age 64 years, 69% male) was evaluated. Depression was measured with the Patient Health Questionnaire and disease-specific HRQoL with the Kansas City Cardiomyopathy Questionnaire. Heart failure severity was assessed with physician ratings of the New York Heart Association (NYHA) functional class. The simultaneous effects of predictor variables on outcomes were estimated using structural equation modeling. Both depression and NYHA functional class independently predicted the physical domain of HRQoL. By contrast, the psychologic domain was only predicted by depression, but not by NYHA functional class. Conclusions: Our results suggest that comorbid depression has an independent impact on both physical and psychologic HRQoL in patients with chronic heart failure after controlling for the severity of heart failure symptoms, while heart failure severity only impacts physical HRQoL. Thus, assessment of comorbid depression may help interpreting reduced HRQoL in heart failure patients. Research seems warranted evaluating whether the amelioration of depression may enhance patients' HRQoL in chronic heart failure. (J Cardiac Fail 2009:15:286-292)