Emergency department visual urinalysis versus laboratory urinalysis

Area of Science:

• Clinical Chemistry
• Point-of-Care Testing
• Emergency Medicine

Background:

• Urinalysis is a common diagnostic tool in emergency departments.
• Visual interpretation of dipstick tests by nurses (NPU) is frequently used.
• Laboratory-performed urinalysis (LPU) using automated methods serves as a reference standard.

Purpose of the Study:

• To compare the diagnostic accuracy of nurse-performed urinalysis (NPU) with laboratory-performed urinalysis (LPU).
• To evaluate the sensitivity and specificity of NPU for detecting common urine analytes.

Main Methods:

• Prospective observational study design.
• Convenience sampling of urine specimens in an emergency practice.
• Nurses performed visual dipstick urinalysis unaware of the study, with the same sample sent for LPU.

Main Results:

• 124 of 140 urinalyses were analyzed.
• NPU demonstrated 100% sensitivity for detecting any of blood, leukocyte esterase, nitrites, protein, glucose, or ketones.
• NPU showed a specificity of 49%, with most false positives attributed to "trace" results.

Conclusions:

• While NPU results differ from LPU, a negative NPU is a reliable indicator of a negative LPU.
• NPU can be a useful screening tool in the ED, particularly for ruling out abnormalities.