Cost-Effective CKD Screening: Urine Test Strips with ACR Readout Show Promise, Study finds

The findings published in BMC Nephrology demonstrated that urine test strip analysis is an effective screening tool for chronic kidney disease in low-risk individuals, with the albumin-to-creatinine ratio exhibiting greater sensitivity and specificity in detecting albuminuria than the protein-to-creatinine ratio (PCR).

Early detection of CKD is crucial for timely intervention and improved patient outcomes. While traditional dipstick proteinuria tests are commonly used, they may lack specificity in identifying at-risk individuals. In recent years, test strip analysis has gained attention as a cost-effective screening method for albuminuria, with studies demonstrating promising sensitivity and specificity. However, many of these studies were conducted in mixed cohorts, including both diagnosed and undiagnosed CKD patients or cases with unclear CKD status. Given these challenges, researchers emphasize the critical role of clinical laboratories in ensuring accurate diagnosis and effective monitoring.

Against the above background, Matthijs Oyaert, Department of Laboratory Medicine, Ghent University Hospital, C. Heymanslaan 10, Ghent, Belgium, and colleagues aimed to assess the effectiveness of qualitative and semi-quantitative albumin-to-creatinine ratio (ACR) and protein-to-creatinine ratio test strip results as screening methods for albuminuria across diverse patient cohorts.

For this purpose, the researchers assessed ACR and PCR in cross-sectional (n = 940) and validation (n = 927) patient cohorts. Semi-quantitative urinary ACR and PCR analyses were conducted using the UC-3500 instrument (Sysmex, Kobe, Japan). The diagnostic accuracy of semi-quantitative ACR and PCR was evaluated against quantitative ACR and PCR as the reference standard.

The study revealed the following findings:

• In the cross-sectional cohort, semi-quantitative ACR at a cut-off of 30 mg/g creatinine showed 78.1% sensitivity and 93.3% specificity, with an overall agreement of over 90% between methods.
• In the validation cohort, sensitivity and specificity improved to 89.9% and 92.1%, respectively.
• Qualitative protein concentration had a sensitivity of 78.6%, while semi-quantitative PCR had a lower sensitivity of 69.8%.

The findings reinforce that urine test strip readouts are a valuable tool for CKD screening in low-risk individuals. When using urine test strips for albuminuria and CKD detection, the ACR readout should be the preferred criterion for reflex testing.

"In our study, urine test strips demonstrated their utility as an effective screening tool for CKD in low-risk individuals. If used for albuminuria and CKD screening, the ACR readout should be the preferred criterion for reflex testing," the authors concluded.

Reference:

Lambrecht, S., Speeckaert, M. & Oyaert, M. Optimization of screening strategy for chronic kidney disease by urine test strips using the albumin-creatinine read-out. BMC Nephrol 26, 130 (2025). https://doi.org/10.1186/s12882-025-04048-9