Lamontagne Annie, Côté Anne-Marie, Rey Evelyne
Department of Obstetrics and Gynaecology, Cité de La Santé de Laval, Laval QC.
Department of Medicine, CHU Sherbrooke, Sherbrooke QC.
J Obstet Gynaecol Can. 2014 Apr;36(4):303-308. doi: 10.1016/S1701-2163(15)30605-8.
To determine the performance of a protein-to-creatinine ratio threshold of 30 mg/mmol in pregnant women investigated for hypertension according to the time of day of the sample.
This prospective study included ambulatory pregnant women investigated for hypertensive disorders. A single voided random urine specimen was obtained to determine the protein-to-creatinine ratio, followed immediately by a 24-hour urine collection. Statistical analyses included Spearman correlation, sensitivity, specificity, predictive values, likelihood ratios, and receiver-operator characteristic curves with 95% confidence intervals. A P value < 0.05 was considered statistically significant.
Among the 91 specimens analyzed, 47.3% showed significant proteinuria in the 24-hour collection and 33% were first morning samples. The protein-to-creatinine ratio and 24-hour urinary protein excretion were highly correlated (r = 0.92, P < 0.001). The diagnostic accuracy of the protein-to-creatinine ratio threshold of 30 mg/mmol was lower in first morning samples than in samples obtained during the rest of the day, with sensitivity 58% and 90%, specificity 93% and 100%, positive predictive value 88% and 100%, negative predictive value 72% and 92%, positive likelihood ratio 8 and not calculable, and negative likelihood ratio 0.45 and 0.1, respectively. The receiver-operator characteristic area under the curve was 0.94 (95% CI 0.86 to 1) for first morning samples and 1.0 (95% CI 0.99 to 1) for other samples.
A protein-to-creatinine ratio threshold of 30 mg/mmol reliably identifies significant proteinuria, but its reliability is reduced in first morning samples. Consequently, such samples should not be used for this purpose.
根据样本采集的时间，确定在因高血压接受检查的孕妇中，蛋白质与肌酐比值阈值为30mg/mmol时的性能表现。
这项前瞻性研究纳入了因高血压疾病接受检查的门诊孕妇。获取一份单次随机晨尿样本以测定蛋白质与肌酐比值，随后立即进行24小时尿液收集。统计分析包括Spearman相关性、敏感性、特异性、预测值、似然比以及具有95%置信区间的受试者工作特征曲线。P值<0.05被认为具有统计学意义。
在分析的91份样本中，47.3%在24小时收集的样本中显示出显著蛋白尿，33%为首次晨尿样本。蛋白质与肌酐比值和24小时尿蛋白排泄高度相关（r = 0.92，P < 0.001）。首次晨尿样本中蛋白质与肌酐比值阈值为30mg/mmol的诊断准确性低于当天其余时间获取的样本，敏感性分别为58%和90%，特异性分别为93%和100%，阳性预测值分别为88%和100%，阴性预测值分别为72%和92%，阳性似然比分别为8和无法计算，阴性似然比分别为0.45和0.1。首次晨尿样本的受试者工作特征曲线下面积为0.94（95%CI 0.86至1），其他样本为1.0（95%CI 0.99至1）。
蛋白质与肌酐比值阈值为30mg/mmol能够可靠地识别显著蛋白尿，但在首次晨尿样本中的可靠性降低。因此，此类样本不应为此目的使用。
