Variability in Urine Culture Reporting by Canadian Microbiology Laboratories

Abstract

OBJECTIVE: To determine the ability of microbiology laboratories to perform and to report urine colony counts.DESIGN: Clinical Microbiology Proficiency Testing program participants received stabilized simulated urine samples. Laboratories were asked to perform the appropriate test and report results.PARTICIPANTS: One hundred and nine clinical microbiology laboratories in British Columbia, Alberta and Nova Scotia.OUTCOME MEASURES: Consistency of reporting was compared with standards for reporting results as described in the SI Manual in Health Care, 2nd edition.RESULTS: The study demonstrated a wide variation in units used for the reporting of results. Ninety-five (87.2%) laboratories reported quantitative urine results in a variety of unit styles. Of those laboratories providing results with units, 80 (84.2%) used one of 10 variations of SI reporting styles. Fifteen (16.8%) laboratories reported metric units in three different styles. Eleven (10.0%) laboratories reported semiquantitative values without stating units. The remaining three (2.8%) did not respond to the survey.CONCLUSIONS: Many clinical microbiology laboratories have not adopted a consistent form of SI units for reporting quantitative urine culture results. This lack of consistency could potentially lead to interpretation confusion.