Emergency department visual urinalysis versus laboratory urinalysis

The primary objective of this study was to compare the results of nurse-performed urinalysis (NPU) interpreted visually in the emergency department (ED) with laboratory performed urinalysis (LPU) interpreted by reflectance photometry.

This was a prospective observational study based on a convenience sample from my emergency practice. Emergency nurses, who were unaware of the study, performed usual dipstick analysis before sending the same urine sample to the laboratory for testing.

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.

Although NPU does not yield identical results to LPU, a negative LPU is expected when the initial NPU in the ED is negative.