Validity and interobserver agreement of reagent strips for measurement of glucosuria

Background. Measurement of glucosuria by means of a visually readable reagent test strip is frequently used in a wide variety of clinical settings. The aim of this study was to evaluate the validity and reliability of this semi-quantitative measurement of glucosuria compared to laboratory measurements of glucose concentrations in urine. Methods. Reagent test strips (Combur(3)Test (R) Roche) from 375 artificially supplemented samples of urine, covering a wide range of glucose concentrations, were independently read by three different observers. Scores of the strips were categorized as 0, 1+, 2+, 3+ or 4+, in ascending degree of glucosuria. Results of the test-strips were compared to the quantitative measurement of urinary glucose concentration in the laboratory. Results. 21.7% of reagent strips readings were discordant with the laboratory measurements ( p