Use of a first-line urine protein-to-creatinine ratio strip test on random urines to rule out proteinuria in patients with chronic kidney disease

Background. Urine protein strip tests are often used in the ward or clinic as first-line measures of proteinuria. The ability of a semi-quantitative meter-read strip test for the protein:creatinine ratio, Multistix*PROR 10LS (Siemens Medical Solutions, Tarrytown, USA), was assessed as a first-line test to exclude significant proteinuria in the monitoring of patients with established chronic kidney disease. Methods. Eighty-six patients attending a hospital renal outpatient clinic collected three random urine samples during a 24-h period. Random urine protein:creatinine ratios measured by the strip test were compared to the laboratory estimation of 24-h protein excretion on that same day. Results. At significant protein excretion of 0.3 g/24 h, the strips elicited negative predictive values in the range of 91.294.1% and negative likelihood ratios of 0.010.12, using all the random urines. Receiveroperator characteristic curve analysis also demonstrated good performance with all samples. Conclusions. The strip test allows the physician to rule out significant proteinuria at the patient consultation on a random urine sample, obviating the need for specially collected samples, and with the added benefit of reducing the need for a lengthy and costly quantitative laboratory follow-up by ~4048%.