Emergency department visual urinalysis versus laboratory urinalysis

Abstract

Objective: The primary objective of this study was to compare the results of nurse-performed urinalysis (NPU) interpreted visually in the emergency department (ED) with laboratoryperformed urinalysis (LPU) interpreted by reflectance photometry. Methods: This was a prospective observational study based on a convenience sample from my emergency practice. Emer - gency nurses, who were unaware of the study, performed usual dipstick analysis before sending the same urine sample to the laboratory for testing. Results: Of 140 urinalyses performed during the study period, 124 were suitable for analysis. When compared with the reference standard LPU, the NPU had an overall sensitivity of 100% (95% confidence interval [CI] 95%-100%) and a specificity of 49% (95% CI 33%-65%) for the presence of any 1 of blood, leukocyte esterase, nitrites, protein, glucose or ketones in the urine. Of 20 falsely positive NPUs, 18 were a result of the nurse recording 1 or more components as "trace" positive. Conclusion: Although NPU does not yield identical results to LPU, a negative LPU is expected when the initial NPU in the ED is negative.