Objective:

To analyze the relationship between proteinuria in 24 hours and the proteinuria/creatinine rate taken from an aliquot of the same sample and analyze the critical variables that may affect its correlation.

Methods:

Clinical, observational, quasi-experimental and prospective research. In 25 hypertensive pregnant women, random, 24-hour urine samples were taken and sent to the laboratory to calculate the protein/creatinine ratio. The concentration of protein in urine was determined by the turbidimetric method and the concentration of creatinine in urine was determined by the colorimetric method of creatinine. Diagnostic efficacy curves and area under the curve were evaluated. The relationship between the protein/creatinine index and proteinuria in 24 hours was evaluated using the Pearson correlation test. Any p-value ≤ 0.05 was considered statistically significant.

Results:

In random urine the average creatinine was 34.58 ± 5.06 mg/dL, the protein was 30,41 ± 8,96 mg/dL. The protein/creatinine index in sporadic urine was 0.20 mg/dL in 21/24 patients (95% confidence interval of 0.00-1); with 87% sensitivity and 100 % specificity, positive predictive value of 100 % and negative predictive value of 21 %, area under the curve of 0.887.

Conclusions:

The protein/creatinine index had a high diagnostic performance with a cut-off point of 0.2 mg/mg and an area under the curve of 0.887. It is equivalent to 24-hour proteinuria, with time-saving advantages and easy interpretation.