Binder L, Smith D, Kupka T, Nelson B, Glass B, Wainscott M, Haynes J
Division of Emergency Medicine, Texas Tech University School of Medicine, El Paso 79905.
Arch Pathol Lab Med. 1989 Jan;113(1):73-6.
A prospective observational study of 229 cases was conducted in a busy ambulatory care setting to evaluate the sensitivity, specificity, predictive values, and accuracy of spot urine urobilinogen and urine bilirubin assays as screening tests for serum liver function test (LFT) abnormalities. Both urine tests exhibited remarkably similar characteristics overall once they were adjusted to maximize accuracy and predictive values (occurring at a normal or abnormal "threshold," respectively, of 3.4 or 5.07 mumol/d for urobilinogen and 0 or 1+ for urine bilirubin). The percentage of cases correctly identified were 81% to 83% for serum bilirubin assays, 68% to 72% for other LFTs, but only 62% to 63% for screens for cases with at least one abnormal LFT finding. Poor sensitivities (47% to 49%) limited the detection of abnormal findings by the screen; both screens were reasonably specific (79% to 89%), but negative predictive values were suitable (89%) for serum bilirubin results only and were prohibitively lower (49% to 50%) in predicting all patients without LFT abnormalities. We conclude that spot urine urobilinogen and urine bilirubin determinations, although good screens for isolated serum bilirubin elevations, have unacceptable statistical properties as predictors of other LFT results due to a high proportion of false-negative results.
在一个繁忙的门诊护理机构中，对229例患者进行了一项前瞻性观察研究，以评估尿胆原和尿胆红素检测作为血清肝功能检查（LFT）异常筛查试验的敏感性、特异性、预测值和准确性。一旦对两项尿液检测进行调整以最大化准确性和预测值（尿胆原正常或异常“阈值”分别为3.4或5.07 μmol/d，尿胆红素为0或1+），它们总体上表现出非常相似的特征。血清胆红素检测正确识别病例的百分比为81%至83%，其他LFT检测为68%至72%，但对于至少有一项LFT异常结果的病例筛查仅为62%至63%。低敏感性（47%至49%）限制了筛查对异常结果的检测；两项筛查的特异性都相当高（79%至89%），但阴性预测值仅对血清胆红素结果合适（89%），而在预测所有无LFT异常的患者时则极低（49%至50%）。我们得出结论，尿胆原和尿胆红素检测，虽然是孤立性血清胆红素升高的良好筛查方法，但由于假阴性结果比例高，作为其他LFT结果的预测指标，其统计学特性不可接受。
