A Comparison of Prediction Equations for Estimating Glomerular Filtration Rates in Elderly Taiwanese Patients with Chronic Kidney Disease

Abstract

BACKGROUND: Chronic kidney disease (CKD) is an emerging chronic condition among aging populations. Different equations have been developed for CKD diagnosis and staging, including the Taiwanese Modification of Diet in Renal Disease (MDRD) and New Taiwanese equations. We compared these and three other equations for estimated glomerular filtration rates (eGFRs) in elderly Taiwanese patients with CKD.METHODS: This was a cross-sectional analysis of 417 patients with CKD stages 3-5. We grouped these patients according to different characteristics and assessed intra-group differences in eGFRs calculated using five equations. The differences in eGFRs for these five equations were assessed by linear regression analysis. The correlation and agreement of the five equations on CKD classification were also examined using the MDRD equation as reference. We also assessed whether a severe CKD stage was associated with higher odds of cardiovascular disease (CVD) after adjusting for traditional risk factors.RESULTS: The mean age of the patients was 75.1 years, 60.2% were men, and 48.4% had CVD. The average serum creatinine level was 2.8 mg/dL, but eGFRs were different in intra-group comparisons. Overall, the correlation and agreement of the five equations on CKD classification were high. The odds of CVD increased among patients with CKD stages 4 and 5 compared with CKD stage 3, especially when using the New Taiwanese equation.CONCLUSION: Statistically significant differences were observed in eGFRs calculated using the five equations, although the clinical implications should be assessed in a longitudinal study. A higher CVD prevalence independent of other traditional risk factors was observed in elderly patients with CKD stages 4 and 5 than in those with stage 3.