Comparison of urine protein-creatinine ratio and urine dipstick test for significant proteinuria in preeclamptic women

• Published in: Therapeutic advances in reproductive health Vol. 18; p. 26334941241288841
• Main Authors: Olisa, Chinedu L, Nwosu, Betrand O, Eleje, George U, Oguejiofor, Charlotte B, Mbachu, Innocent I, Ogabido, Chukwudi A, Njoku, Tobechi K, Okafor, Chidinma C, Okechukwu, Zebulon C, Okeke, Chukwunwendu F, Okonkwo, Ifeanyi O, Okaforcha, Emmanuel I, Enechukwu, Chukwunonso I, Ilika, Chito P, Nnabuchi, Obinna K, Osuafor, Ugochukwu H, Ugwuoroko, Harrison C, Egwuatu, Emmanuel C, Andeh, Martin C, Okafor, Chigozie G
• Format: Journal Article
• Language: English
• Published: England SAGE Publishing 01-01-2024
• Subjects: protein/creatinine ratio; preeclampsia; significant proteinuria in pregnancy; hypertension; proteinuria
• DOI: 10.1177/26334941241288841
• EISSN: 2633-4941

Assessing for significant proteinuria in pregnancy (SPIP) stands as a key indicator for diagnosing preeclampsia. However, the initial method typically employed for this assessment, the urine dipstick test, often yields inaccurate results. While a 24-h urine collection is considered the most reliable test, its implementation can lead to delays in diagnosis, potentially affecting both maternal and fetal well-being. The urine protein-creatinine (P/Cr) ratio can be used as an alternative to 24-h urine protein analysis, but its diagnostic accuracy has remained uncertain. There is a need to compare the diagnostic accuracy of urine P/Cr ratio and dipstick urinalysis for SPIP, especially in resource-poor settings.
To determine and compare the diagnostic accuracy of urine P/Cr ratio and dipstick urinalysis in a spot urine specimen for the diagnosis of SPIP among women evaluated for preeclampsia using 24-h urine protein excretions as a gold standard.
This is a comparative cross-sectional study.
The study involved 82 singleton pregnant women evaluated for preeclampsia from 20 weeks of gestation who underwent dipstick and P/Cr ratio tests in the same urine sample. Women at risk of preeclampsia were given a specimen container for the collection of urine samples on an outpatient basis. Participants were trained and told to collect the urine sample 24 h prior to their next antenatal appointment. However, those on admission and evaluated for preeclampsia had their 24-h urine collected in the hospital. The outcome measures included sensitivity, specificity, positive predictive value, negative predictive value, likelihood ratio and accuracy for the two tests. Significant proteinuria was defined as a P/Cr ratio >0.27 or ⩾2+ of proteinuria on the dipstick test. Preeclampsia was confirmed in women with both high blood pressure and SPIP.
The mean age of participants was 28.65 ± 5.76 years. Comparatively, the diagnostic accuracy (91.46% (95% CI = 83.29-96.59) vs 59.76% (95% CI = 48.34-70.44),
 = 0.001), sensitivity (94.74% vs 70.00%,
 = 0.021), specificity (84.00% vs 43.75%,
 = 0.001), negative predictive value (87.50% vs 48.28%,
 = 0.003) and positive predictive value (93.10% vs 66.04%,
 = 0.001), respectively, were higher for the spot urine P/Cr ratio than dipstick test. In addition, the positive likelihood ratio and the negative likelihood ratio for spot urine P/Cr ratio versus dipstick test were (1.93 vs 1.24) and (0.07 vs 0.69), respectively.
The spot urine P/Cr has superior diagnostic accuracy in the determination of significant proteinuria in pregnant women being evaluated for preeclampsia than the widely used dipstick test. A more robust multicenter study is needed to compare the diagnostic accuracy of spot urine PCR with the standard 24-h urine protein in low-income settings.