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

Background: Heart failure is an increasing global health problem which adversely affects all aspects of a patient's health-related quality of life (HRQOL). Purpose: The hypothesized causal model of HRQOL in Thai heart-failure patients was based on Wilson and Cleary's HRQOL conceptual model. We examined causal relationships among bio-physiological status, symptoms, functional status, general health perception (GHP), and HRQOL shown in the model, and added an additional item-social support. Methods: A stratified four-stage random sampling method was used to obtain 422 heart-failure patients 18 years of age and older who visited nine outpatient hospital clinics from five regions of Thailand including metropolitan Bangkok. In addition to the participants' personal medical records, research instruments consisted of a personal information questionnaire, the Enhancing Recovery in Coronary Heart Disease Social Support Instrument, Cardiac Symptom Survey, the New York Heart Association functional classification system, a 100-mm horizontal visual analogue scale of GHP, and the Minnesota Living with Heart Failure Questionnaire. Data were analyzed using SPSS and AMOS computer programs. Results: The model fit well with the empirical data (chi(2) = 19.87, df = 13, p = 0.10, GFI = 0.99, and RMSEA = 0.04). Symptom status was the most influential factor affecting HRQOL by both direct and indirect effects through functional status and GHP. Social support was the least influential factor affecting HRQOL. Social support had a negative direct effect on HRQOL, but had a positive indirect effect on HRQOL through symptom status and GHP. Conclusions: HRQOL was affected by each variable proposed in our causal model of HRQOL in Thai heart-failure patients. Symptom status had the strongest effect on HRQOL. Clinical Relevance: A comprehensive symptom management and prevention program that includes the described health outcome measures could lead to improved HRQOL for Thai heart-failure patients, and perhaps others.