High Risk of Renal Failure in Stage 3B Chronic Kidney Disease is Under-recognized in Standard Medical Screening

Background: The objective of this study was to determine the risk of renal failure in patients with under-recognized chronic kidney disease (CKD) in the self-pay standard medical screening program of health management centers. Methods: The abbreviated Modification of Diet in Renal Disease equation was used to calculate the estimated glomerular filtration rate (eGFR) of study subjects. Study subjects with eGFR less than 60 mL/min/1.73 m 2 but with normal results of routine assessment, including serum creatinine, blood urea nitrogen, urinalysis and kidney ultrasound, were defined as having under-recognized CKD. Episodes of renal failure requiring dialysis within 2 years in subjects with stage 3 to stage 5 CKD were evaluated. Results: A total of 15,817 subjects were recruited and 28.4% of subjects were identified by routine assessments as having a kidney problem. The prevalences of CKD 3A, 3B, 4 and 5 were 8.3%, 1.9%, 0.3% and 0.2%, respectively. All subjects with stages 4 and 5 CKD had abnormal serum creatinine levels, but 48.7% of 1,507 subjects with stage 3 CKD (stage 3A, n = 713; stage 3B, n = 21) had normal routine assessments. Subjects with under-recognized stage 3B CKD had the highest risk (20%) of developing renal failure compared to subjects with stages 3–5 CKD and abnormal results of routine assessments. Conclusion: Identifying subjects with CKD stage 3 by the eGFR equation, especially in stage 3B, is advantageous in detecting the risk of renal failure over the routine clinical assessment that is currently carried out by health management institutions in Taiwan. [J Chin Med Assoc 2010;73(10):515–522]