Can we reduce the interference of vitamin C and PH in urinalysis?

Urinalysis is often interfered by vitamin C and PH. This study was to evaluate the interference of vitamin C and PH in urinalysis, and minimize the risk to make the effective communication. 732 leftover urine samples in which the concentration of vitamin C was 0.0 mmol/L and either of the test-strip results (Glucose, Blood, Bilirubin, Leucocyte, Nitrite, Protein, Ketone) was positive that were collected. The interference test checked out using these leftover urine samples. When the chemical protein module was positive, the sulfosalicylic acid test performed to confirm the positive results. About 27% of urine samples were vitamin C (p-value < 0.05). False-positive protein occurred at any samples, but higher when urine PH is greater than or equal to 8.0. In summary, to minimize the risk of vitamin C and PH in urinalysis, the laboratory should pay more attention to its conditions. Also, do more to help guarantee the accuracy of the urinalysis results and to give more comments to doctors to achieve effective communication.