Can the urine dipstick test be used as a proteinuria screening test?

INTRODUCTION: The present study aimed to evaluate the diagnostic performance of the chemical dipstick protein measurement method, which can be used for screening purposes, in the detection of proteinuria.

METHODS: The results from 795 individuals were retrospectively scanned. In order to evaluate the urine dipstick’s accuracy in detecting proteinuria, the current study accepted protein/creatinine ratio (PCR) as the reference value, and three different criteria were used according to different age groups [PCR: ≥ 0.2 g/g (>2 years), ≥ 0.5 g/g (6 months-2 years), and ≥ 0.8 g/g (0-6 months)]. While evaluating diagnostic sensitivity, specificity, positive predictive value, and negative predictive value, two cut-off values [trace and 1(+)] were evaluated. Area under the curve (AUC) by Receiver operating characteristic analysis were analyzed.


RESULTS: The calculated sensitivity levels were lower than 70% for all age groups, with an AUC of 0.680 ± 0.237, 0.780 ± 0.07, and 0.768 ± 0.018 for the age groups of 0–6 months, 6 months–2 years, and > 2 years, respectively.

DISCUSSION AND CONCLUSION: When the PCR was taken as a reference for proteinuria, the chemical dipstick test only proved suitable for screening proteinuria in the >6 months age group. Nonetheless, its performance could benefit from further improvement. Although the use of dipsticks is fast, simple, and inexpensive, this research indicates that they cannot replace PCR and 24-hour urine protein amount tests in the diagnosis and follow-up of renal diseases, which are generally known to be asymptomatic until their progression and complications are detected.