Measurement of health-related quality of life in patients with chronic kidney disease in Japan with EuroQol (EQ-5D)

Chronic kidney disease (CKD) is a health-related quality-of-life (HRQOL) deteriorating disease which is not only a public health but also a socioeconomic problem. Interest in developing cost-effective interventions to control CKD has increased. The aim of this study was to measure HRQOL in terms of quality-adjustment weights for cost-effectiveness analysis using EQ-5D in patients with CKD. The relationships between the measured HRQOL and clinical indices/complications were also analyzed. EQ-5D, a generic preference-based instrument, was administered to 569 CKD outpatients at Tsukuba University Hospital between November and December 2008. The response rate was 94.4% (537/569). Data on sex, age, creatinine, hemoglobin, serum albumin and eGFR were obtained from the patients' records. Data on the presence of complications such as hypertension, diabetes, and history of cardiovascular disease (CVD) were also retrieved. Measured quality-adjustment weights by the CKD stage were 0.940 (95% CI 0.915-0.965), 0.918 (0.896-0.940), 0.883 (0.857-0.909), 0.839 (0.794-0.884), and 0.798 (0.757-0.839) for stages 1-5, respectively. The decrease in weight was significant by ANOVA (P < 0.0001), and the weight for all stages was 0.885 (0.871-0.898). There was a positive relationship between hemoglobin/serum albumin and the weight. The presence of hypertension lowered the weight from 0.910 (0.885-0.936) to 0.874 (0.858-0.891), diabetes from 0.901 (0.886-0.917) to 0.840 (0.811-0.869), and CVD from 0.892 (0.878-0.906) to 0.783 (0.718-0.848). HRQOL decreases with progression of CKD stage and/or presence of anemia, undernutrition, hypertension, diabetes, or history of CVD.