Reilly Patricia, Mills Laura, Bessmer Daniel, Jimenez Celia, Simpson Patrick, Burton Mark
Immunology and Microbiology Laboratories, Wilford Hall Medical Center, Lackland AFB TX, USA.
Clin Lab Sci. 2002 Winter;15(1):9-12.
This study examined the utility of performing urine cultures on biochemically negative urine specimens and details the implementation of a policy to cancel these cultures. Four reactions of the Multistix SG (Bayer, Elkhart IN) urine dipstick (protein, occult blood, leukocyte esterase, and nitrite) were used as biochemical indicators. A three-month retrospective study examining the results of 843 urinalysis/ urine culture pairs indicated that one-third of these cultures were probably unnecessary (negative dipstick/negative culture). Based on these results, a policy was implemented to screen those urine samples having both a urinalysis and urine culture ordered. Over a six-month period, 6,192 urine specimens were evaluated. Of these, 36% (2,260 cultures) were cancelled. Of the 3,932 samples cultured 22.4% (883) were true positives (positive dipstick/positive culture) while 31.6% (1245) had a positive dipstick but grew organisms considered contaminants. The false positive rate was 40% (positive dipstick/negative culture), and the false negative rate was 6%. Implementation of this policy reduced the number of urines cultured by 36%.
本研究检验了对生化指标阴性的尿液标本进行尿培养的效用，并详细说明了取消这些培养的政策实施情况。使用Multistix SG（拜耳公司，印第安纳州埃尔克哈特）尿试纸条的四项反应（蛋白质、隐血、白细胞酯酶和亚硝酸盐）作为生化指标。一项为期三个月的回顾性研究，对843对尿液分析/尿培养结果进行了检查，结果表明其中三分之一的培养可能是不必要的（试纸条阴性/培养阴性）。基于这些结果，实施了一项政策，对那些同时开具了尿液分析和尿培养医嘱的尿液样本进行筛查。在六个月的时间里，共评估了6192份尿液标本。其中，36%（2260次培养）被取消。在3932份进行培养的样本中，22.4%（883份）为真阳性（试纸条阳性/培养阳性），而31.6%（1245份）试纸条阳性但培养出的微生物被视为污染物。假阳性率为40%（试纸条阳性/培养阴性），假阴性率为6%。该政策的实施使培养的尿液数量减少了36%。
