Health-Related Quality of Life according to Renal Function: Results from a Nationwide Health Interview and Examination Survey.

BACKGROUND Most studies on health-related quality of life (HRQoL) in chronic kidney disease (CKD) focus on patients with end-stage kidney disease although they represent a small proportion of patients with CKD. We aimed to analyze HRQoL according to glomerular filtration rate (GFR) categories in a population-based sample of adults living in Germany. METHODS Data from the German health interview and examination survey conducted from 2008 to 2011 were used. Participants with valid interview and examination data aged 40-79 years were included (n = 5,159). Serum creatinine levels were used to calculate estimated GFR via the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. We classified kidney function in GFR categories according to the Kidney Disease Improving Global Outcomes Initiative (KDIGO) guidelines on CKD: G1 (high): ≥90 mL/min/1.73 m2, G2 (normal): 60-89 mL/min/1.73 m2, G3a (mildly decreased): 45-59 mL/min/1.73 m2, G3b (moderately decreased): 30-44 mL/min/1.73 m2, G4/5 (severely decreased/end-stage kidney disease): <30 mL/min/1.73 m2. HRQoL was evaluated with the Short Form Health Survey (SF-36). Different multivariate linear and logistic regression models were used to analyze the association of HRQoL with GFR categories. RESULTS Overall, 5.9% had a GFR <60 mL/min/1.73 m2 (corresponding to categories G3a, G3b, and G4/5). Compared to category G2 linear regression showed a decline in physical HRQoL in categories G3a (-2.34, p = 0.004), G3b (-5.37, p = 0.009), and G4/5 (-4.82, p = 0.117). No decline in mental HRQoL was detected with increasing GFR categories. Categories G3a to G4/5 were significantly associated with a low perceived general state of health (G3a: odds ratio [OR] = 2.03, p = 0.001; G3b: OR = 3.01, p = 0.009; G4/5: OR = 8.70, p = 0.016) when compared to category G2. CONCLUSION In a representative sample of adults living in Germany, both physical HRQoL and the perceived general state of health are already significantly reduced in category G3a.