A causal model of health-related quality of life in Thai heart failure patients

Abstract

The purpose of this study was to examine the causal relationship among bio-physiological status (LVEF), social support, symptom status, functional status (NYHA), general health perception, and health-related quality of life (HRQOL) in Thai heart failure patients. The hypothesized causal model of HRQOL in Thai heart failure patients was based on Wilson and Cleary’s Health-Related Quality of Life Conceptual Model. Stratified four stage random sampling was employed to obtain the sample of 422 heart failure patients aged 18 years and above who visited nine hospitals from four regions of Thailand and metropolitan Bangkok. Research instruments consisted of Personal Information Questionnaire, the personal LVEF medical record sheet, the ENRICHD Social Support Instrument (ESSI), the Cardiac Symptom Survey (CSS), the subjective NYHA functional classification, a General Health Perception, and the Minnesota Living with Heart Failure Questionnaire (MLHFQ). Data were analyzed using SPSS and AMOS computer programs. Goodness of fit indices indicated that the model fitted well with the empirical data ([chi square] =19.87, df = 13,[chi square] /df =1.53, p = 0.10, GFI = 0.99, AGFI = 0.97, and RMSEA = 0.04). The overall model explained approximately 58% of the variance in overall health-related quality of life in Thai heart failure patients. Symptom status of heart failure was the most influential factor affecting HRQOL by having both negative direct and indirect effects through functional status and general health perception ([beta] = -0.69, p <.0001). In addition, functional status (NYHA) had negative direct and indirect effects on HRQOL through general health perception ([beta] = -0.32, p <.05). General health perception had only a positive direct effect on HRQOL ([beta] = 0.24, p < .0001). Bio-physiological status (LVEF) had a positive indirect effect on HRQOL through functional status and general health perception (b = 0.16, p< .0001). However, social support was the least influential factor affecting HRQOL ([beta] = 0.04, p < .05). It had a negative direct effect on HRQOL, but a positive indirect effect on HRQOL through symptom status and general health perception. The findings indicated the prominent components of nursing intervention focusing on maintaining or enhancing HRQOL in Thai heart failure patients The intervention components should consist of symptom controlling and symptom management to decrease symptom frequency and symptom severity. This will help heart failure patients to maintain or improve their functional ability to perform their normal daily activities, and their self-care ability. Nurses should consider about bio-logical status, social support, and general health perception and some mediator factors such as age, gender, affecting HRQOL in planning the intervention.