Optimal bedside urinalysis for the detection of proteinuria in hypertensive pregnancy: a study of diagnostic accuracy

JJS Waugh, SC Bell, MD Kilby…�- …�Journal of Obstetrics�…, 2005 - Wiley Online Library
JJS Waugh, SC Bell, MD Kilby, CN Blackwell, P Seed, AH Shennan, AWF Halligan
BJOG: An International Journal of Obstetrics & Gynaecology, 2005Wiley Online Library
Objective To compare semi‐quantitative visual and automated methods of urine testing with
fully quantitative point of care urinalysis for the detection of significant proteinuria (0.3 g/24
hours) in pregnancy complicated by hypertension. Design A prospective comparative study.
Setting A large teaching maternity hospital. Sample One hundred and seventy‐one pregnant
women referred to the obstetric day‐care unit for assessment of newly arisen hypertension.
Methods Early morning urine specimens were tested with four dipstick techniques (Multistix�…
Objective  To compare semi‐quantitative visual and automated methods of urine testing with fully quantitative point of care urinalysis for the detection of significant proteinuria (0.3 g/24 hours) in pregnancy complicated by hypertension.
Design  A prospective comparative study.
Setting  A large teaching maternity hospital.
Sample  One hundred and seventy‐one pregnant women referred to the obstetric day‐care unit for assessment of newly arisen hypertension.
Methods  Early morning urine specimens were tested with four dipstick techniques (Multistix 8SG visual and automated and microalbumin/creatinine ratio visual and automated; Bayer, Elkhart, USA) as well as a fully quantitative measure of the microalbumin creatinine ratio with the DCA 2000 (a point of care assay for albumin; Bayer). These results were compared to a 24‐hour urine protein measurement and measures of diagnostic accuracy/prediction are reported.
Main outcome measures  Significant proteinuria (≥0.3 g/24 hours) measured by laboratory assay.
Results  Automated dipstick urinalysis using the Clinitek 50 has significantly better predictive values for significant proteinuria (LR+ 4.27, 95% CI 2.78 to 6.56; LR 0.225, 95% CI 0.14 to 0.37) than conventional visual dipstick urinalysis (LR+ 2.27, 95% CI 1.47 to 3.51; LR 0.635, 95% CI 0.49 to 0.82). Dipstick microalbumin/creatinine ratio testing did not improve overall detection rates with automated or visual testing. Fully quantitative point of care measurement of albumin/creatinine ratio (ACR) was significantly better than any dipstick technique (LR+ 14.6, 95% CI 6.74 to 31.8; LR 0.069, 95% CI 0.030 to 0.16).
Conclusions  This study confirms that in pregnancy automated dipstick urinalysis is a more accurate screening test for the detection of proteinuria than visual testing. ACR testing can offer a significant improvement over conventional urinalysis if a fully quantitative method of detection is employed that uses pregnancy‐specific thresholds. Dipstick assessment of ACR does not improve the detection rate of significant proteinuria.
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