Improving productivity: total urinalysis vs. reflex to microscopy

have shown that omitting microscopy exams results in missed diagnosis, which of course causes repeated specimen collection and additional laboratory testing. A study authored by Nancy Brunzel and Diane Berry analyzing 709 routine specimens revealed reflexing to microscopy resulted in one in four patient samples being overlooked for pathological conditions. The authors reported the negative predictive value (NPV) for their study using dipstick results and reflexing to microscopy was just 75 percent. Brunzel and Barry highlighted the omission of the presence of blood and bacteria in normal samples. Their study reported more than 25 percent of patients were misdiagnosed for microhematuria when relying solely on urine dipstick result. This misdiagnosis is rather concerning as the presence of blood in urine is clinically significant, especially for males. Urine chemistry dipsticks detect for blood by measuring peroxidase activity of red blood cells U rinalysis provides valuable information, speaking not only to the well-being of the renal and urinary systems, but also to identifying metabolic, hemolytic and other pathological conditions. Total urinalysis comprises of macroscopic (visual observation), chemical (dipstick) and microscopic (urine sediment) analysis. In most, if not all labs, macroscopic analysis is performed at the same time as the chemical analysis. Urine chemistry dipsticks test as many as 12 analytes that include blood (hemoglobin), protein, glucose and other urinary and metabolic biomarkers. Microscopic analysis is a visual examination — qualitative and quantitative — of cellular and formed particles in the urine. Reflex to microscopy refers to omitting normal specimens and only performing microscopic exams on urine specimens with abnormal dipstick results. This is often common practice when manual microscopy is used to examine urine sediment, as it is one of the most tedious and time-consuming processes in the clinical laboratory. Advances in automated urine microscopy analyzers have significantly improved the workflow efficiencies and diagnostic proficiencies of modern urinalysis. However, despite technical advances, even current users of automated urinalysis systems remain committed to the “old-school” practice of reflexing to microscopy as a continuous effort to improve productivity in the clinical laboratory.