Screening of Chronic Kidney Disease in Primary Health: Comparison of the Urine Dipstick Albumin-to-Creatinine Ratio and Dipstick Proteinuria

Abstract

Background: Chronic kidney disease (CKD) needs to be detected early in order to prevent a poor outcome in the general population. A semiquantitative evaluation based on a dipstick has become available to detect the urinary albumin-to-creatinine ratio (ACR) and proteinuria simultaneously in spot urine samples. The aim of this study was to compare dipstick ACR with proteinuria for CKD screening in a primary healthcare setting. Methods: This cross-sectional study analyzed 88,479 subjects who underwent a health check up at 16 health promotion centers in 13 Korean cities. Dipstick ACR and proteinuria was measured using the automated urine test strip analyzer UC-3500 (Sysmex, Kobe, Japan). CKD definition and risk categories according to the 2012. Kidney disease: Improving Global Outcomes guidelines were created using a combination of eGFR and albuminuria. Albuminuria was defined using dipstick ACR ≥ 30 mg/g and dipstick proteinuria as ≥ trace or protein-to-creatinine ratio (PCR) ≥ 150 mg/g. Results: The prevalence of CKD using dipstick ACR, proteinuria, and PCR were 16.3%, 12.7%, and 11.9%, respectively. The concordance rates between the dipstick ACR-and proteinuria- or PCR-based CKD risk categories were 88.76% (κ = 0.567) and 92.06% (κ = 0.683), respectively. On being grouped according to dipstick proteinuria, CKD risk categories would be underestimated than be overestimated. 37.2% and 37.6% of the subjects with ≥ moderately increased CKD risk using ACR-based category were reclassified into lower risk CKD using dipstick proteinuria (≥ trace) and PCR, respectively. Conclusion: The CKD risk category using dipstick proteinuria the ACR-based CKD risk category. These data suggest that screening of using dipstick ACR is recommended in a primary healthcare settings.