Abstract
Microbiology laboratories in Alberta, Canada, were surveyed to determine the quantitative interpretive criteria used to routinely read and report Gram stains. There was a wide variability in the quantitative reporting criteria cited for both cells and bacteria, with only 11 of 32 (34.4%) laboratories surveyed using the criteria recommended by the external proficiency-testing program. Lack of standardized criteria not only poses a problem in the grading of proficiency testing results but may also impact the quality of patient care.