[Rationalization of urine analysis while maintaining diagnostic accuracy (author's transl)]

Area of Science:

• Clinical chemistry
• Urinalysis
• Diagnostic pathology

Background:

• Microscopic examination of urinary sediment is a cornerstone of routine urinalysis.
• Standardized methods and technician variability can impact the accuracy of sediment analysis.
• Test-strip urinalysis offers a rapid screening method for various urine analytes.

Purpose of the Study:

• To evaluate the efficiency and diagnostic yield of using test-strips for screening morning urine samples.
• To compare the effectiveness of test-strip screening against traditional microscopic urinary sediment examination.
• To identify potential sources of error in microscopic urinary sediment analysis.

Main Methods:

• Screening of 720 morning urine samples using test-strips for white blood cells (WBC), red blood cells (RBC), and protein.
• Subsequent microscopic examination of urinary sediment for comparison.
• Analysis of discrepancies between test-strip results and microscopic findings.

Main Results:

• Test-strip screening reduced the need for microscopic examinations by approximately 50%.
• No significant number of clinically important findings were missed (4.4% missed).
• A notable percentage (21.3%) of false-negative sediment findings were identified, often due to cell lysis or method standardization issues.

Conclusions:

• Test-strip screening rationalizes clinical routine urinalysis, saving time.
• This screening approach can improve the detection of significant findings compared to un-screened sediment examination.
• Addressing issues like cell lysis and standardization is crucial for accurate microscopic urinalysis.