Background: Chronic kidney disease (CKD) is a major global problem and is also associated with a decreased health-related quality of life (HRQOL). The aim of this study was to evaluate measured HRQOL based on the new CKD classification including proteinuria stage, and the effect of measured HRQOL on CKD progression and clinical outcomes over a 3-year period.
Methods: EuroQol (EQ-5D), a generic preference-based questionnaire, was administered to 537 CKD outpatients at the University of Tsukuba Hospital between November and December 2008. We evaluated disease progression in CKD patients including the incidence of end-stage kidney disease (ESKD), cardiovascular disease (CVD) and all-cause mortality over a 3-year follow-up period.
Results: The proportions progressing to the higher stages were 32.6, 20.0, 36.6, 39.5, and 45.8 % from glomerular filtration rate (GFR) stages (G) 1-4, respectively. The proportion progressing to ESKD (G5D) was 0.7 % from G2, 3.9 % from G3b, 20.8 % from G4 and 63.4 % from G5. The incidence of CVD and/or death was 1.2, 4.6, 4.9, 5.3, 8.3 and 21.1 % from G1-G5, respectively. The quality-adjustment weights at G4-5 were significantly lower than at G1-2 and the weights at proteinuria stage (A) 3 were significantly lower than at A1-2. The quality-adjustment weights of patients with events such as 50 % estimated GFR decline, dialysis, CVD, and/or death were significantly lower than those without events.
Conclusion: We showed CKD progression and clinical outcomes over a 3-year period. Quality-adjustment weights in CKD patients were associated with not only disease progression such as initiation of dialysis treatment and incidence of CVD events and all-cause death, but also the level of proteinuria at baseline.