Accuracy and precision of urinary pH determinations using two commercially available dipsticks

Area of Science:

• Clinical Chemistry
• Diagnostic Accuracy
• Urinalysis

Background:

• Urinary pH is a key diagnostic parameter.
• Dipstick urinalysis is a common point-of-care testing method.
• Accurate pH determination is crucial for patient management.

Purpose of the Study:

• To evaluate the accuracy and precision of commercially available urinary pH dipsticks.
• To assess variations in dipstick performance across different products and technologists.
• To determine the reliability of dipstick urinalysis for urinary pH measurement.

Main Methods:

• Two commercial urinary pH dipstick products were assessed.
• Seventeen Medical Technologists (MT) with ASCP certification participated.
• Testing covered a urinary pH range from 4.5 to 9.0.
• Evaluated accuracy, reproducibility, and inter-technologist/inter-product variability.

Main Results:

• Significant variability was observed among technologists in pH determination.
• Substantial differences in accuracy were noted between the two dipstick products.
• Results varied considerably depending on the true urinary pH level.
• Both excellent and poor results were obtained, influenced by technologist and pH.

Conclusions:

• Commercially available urinary pH dipsticks exhibit considerable variability in accuracy and precision.
• Technologist skill and the specific dipstick product significantly impact urinary pH measurement reliability.
• Careful consideration of these factors is necessary for accurate urinalysis interpretation.