Differences between psychometric and utility measures on quality-of-life and their associated factors in hemodialysis patients

Objectives: The aim of this study was to compare quality-of-life (QOL) scores from WHOQOL-BERF (TW) and QOL values from the standard gamble (SG) method or visual analogue scale (VAS) method in hemodialysis (HD) patients. Comparisons were also made among associated factors of global scores, SG and VAS values. Methods: A cross sectional survey of QOL was conducted in 506 HD patients from 13 HD centers in Taipei and Keelung areas. Instruments included: (1) WHOQOL-BREF (TW) from which scores of global QOL. physical, psychological, social relationship and environment domains were calculated; (2) QOL values of SG and VAS methods based on utility theory. Results: In HD patients, SG values were significantly higher than VAS values, global score and four domains. In contrast, VAS values were about the same as psychometric scores. Pearson correlations of SG values and peychometric scores (0.10-0.20) were relatively lower than those of VAS values and psychometric scores (0.22-0.53). Associated factors of SG values were education, religion comorbidity, urea reduction rate, erythropoietin dosage, with total R² only 0.20. Associated factor of global QOL scores were area, comorbidity and hemoglobin level, with R ² 0.42. Associated factors of VAS values were education and family monthly income, with total R² 0.42. Conclusion: Total QOL measures of SG, VAS, and global QOL from WHOQOL-BREF (TW) in HD patients were significantly different and their associated factors were complex.