Diagnostic accuracy of urine dipstick for proteinuria in older outpatients

• Published in: Kidney research and clinical practice 2014-12, Vol.33 (4), p.199
• Main Authors: Dong Min Lim, Dong Young Lee, Soung Ha Cho, One Zoong Kim, Sang Woo Cho, Su Kyoung An, Hwe Won Kim, Kyoung Hyoub Moon, Myung Hee Lee, Beom Kim
• Format: Article
• Language: Korean
• Subjects: Albuminuria; Proteinuria; Reagent strips; ROC curve
• ISSN: 2211-9132

Background: The urine dipstick is widely used as an initial screening tool for theevaluation of proteinuria; however, its diagnostic accuracy has not yet beensufficiently evaluated. Therefore, we evaluated its diagnostic accuracy using spoturine albumin/creatinine ratio (ACR) and total protein/creatinine ratio (PCR) inproteinuria. Methods: Using PCR Z0.2 g/g or Z0.5 g/g and ACR Z300 mg/g or Z30 mg/g asthe reference standard, we calculated the diagnostic accuracy profile: sensitivity,specificity, positive and negative predictive value, and the area under the curve(AUC) of the receiver operating characteristic curve. Results: PCR and ACR were available for 10,348 and 3,873 instances of dipsticktesting. The proportions with PCR Z0.2 g/g, Z0.5 g/g and ACR Z300 mg/g,Z30 mg/g were 38.2%, 24.6% and 8.9%, 31.7%, respectively. The AUCs for PCRZ0.2 g/g, Z0.5 g/g, and ACR Z300 mg/g were 0.935 (trace: closest to ideal point),0.968 (1þ), and 0.983 (1þ), respectively. Both sensitivity and specificity were480% except for PCR Z0.5 g/g with trace cutoff. For the reference standard of ACRZ30 mg/g, the AUC was 0.797 (trace) and the sensitivity was 63.5%. Conclusion: Urine dipstick test can be used for screening in older outpatients withACR Z300 mg/g or PCR as the reference standard for proteinuria. However, wecannot recommend the test as a screening tool with ACR Z30 mg/g as the referenceowing to its low sensitivity.