Urine Culture Contamination: A College of American Pathologists Q-Probes Study of 127 Laboratories (Report)
Some contamination of urine specimens may be unavoidable. A College of American Pathologists (CAP) Q-Probes study (1) published in 1998 found that the contamination rate was as high as 36.8% for some institutions. The same study found that the use of central processing areas, refrigeration, urine screening systems, specimen preservatives, provision of written collection instructions or special collection kits, and thermally insulated specimen transport containers were not found to be associated with low specimen contamination rates in a multivariate analysis. It is not cost-effective for a laboratory to provide definitive workup of contaminated cultures because repeat cultures yield better results. (2) Inappropriate reporting of contaminated urine culture results may lead to inadequate therapy, increased costs, and poor patient outcomes. Repeat visits to re-collect a urine specimen will lead to patient dissatisfaction and delay of treatment.