Standardization of the urine microscopic examination

Abstract

Two standardized systems for examining urine sediment, UriSystem and the Kova System, were compared using urines from renal patients, hospitalized patients, and a normal population. Red blood cells and white blood cells were counted with each system and counts were placed into one of three predetermined clinically relevant categories: normal, suspicious, or diagnostic. In addition, cell counts were evaluated to compare how the systems categorized cell counts when dipstick results for blood, nitrite, and leukocyte esterase were negative. Results indicated that the UriSystem placed patient values into a category of higher relevance than the Kova system. When the reagent strip test results were negative, cell counts by the UriSystem were more likely to be in the suspicious category, indicating a possible need for further patient work-up than the counts done by the Kova system. Normal ranges of the microscopic sediment of the urinalysis must be re-evaluated using standardized systems such as those studied.