What is a major cause of error in protein testing in urine?

In the context of urine protein testing, QUATS, or quaternary ammonium compounds, represent a significant source of error. These compounds can interfere with the reagent strips used in testing for protein due to their surfactant properties, falsely increasing the readings of protein concentrations. This interference can lead to inaccurate results, causing clinicians to potentially misinterpret the presence and severity of proteinuria.

Other factors, while they may influence urine composition or testing accuracy, do not have as pronounced an effect as QUATS on protein detection. For example, the presence of urea can affect certain types of urine tests but does not directly interfere with protein reaction mechanisms in the way QUATS does. Specific gravity is a measure of concentration and can indicate dilution or concentration of the sample but does not inherently disrupt protein testing. Color variations in urine can reflect different concentrations of substances but again do not interfere with the specific chemical reactions used to detect protein. Thus, QUATS is recognized as a critical factor leading to erroneous protein readings in urine tests.