Abstract 18464: How Does Illness Severity Affect Quality of Life in Adults with Heart Failure?
Introduction: Health-related quality of life (HRQOL) is significantly decreased in patients with heart failure (HF), especially in those with worse illness severity. The underlying processes explaining how illness severity influences HRQOL are unclear.
Purpose: To test the hypothesis that sleep quality, functional outcomes of sleep, depression, and health perception mediate the effect of illness severity (NYHA functional class) on HRQOL in HF.
Methods: Adults with a confirmed diagnosis of stage C chronic HF were enrolled. Those with severe depression, dementia, a prior significant neurologic event, terminal illness, or recent drug or alcohol abuse were excluded. Baseline data collected from 279 HF patients was analyzed using multiple regression modeling while controlling for age, gender, ethnicity and data collection site. Subjects completed the Kansas City Cardiomyopathy Questionnaire (HRQOL), the Pittsburgh Sleep Quality Index Questionnaire (sleep quality), the Functional Outcomes of Sleep Questionnaire (functional outcomes of sleep), the Patient Health Questionnaire (depression) and a self-rating of perceived health. Bootstrapping methodology with percentile confidence intervals was used to test for indirect effects of multiple mediators.
Results: Mean age was 62 (SD = 12.47) years with 36% females. Most patients (76%) were either NYHA class III or IV. In multiple regression analysis, illness severity was significantly associated with HRQOL (β = -6.055, p = 0.025). In the multiple mediation model, sleep quality, functional outcomes of sleep, depression and health perception significantly mediated the effect of illness severity on HRQOL [total indirect effect is -13.7768; 95% CI of -18.2833 to -9.2502], with point estimates of -1.9818, -4.2605, -2.3010 and -5.2335, respectively. Pairwise contrasts revealed that health perception was the strongest mediator of the relationship.
Conclusions: In conclusion, sleep quality, functional outcomes of sleep, depression and health perception combined may be important targets for intervention to improve the HRQOL of HF patients.
- © 2010 by American Heart Association, Inc.