title: Estimating the precision of disc diffusion antibiotic susceptibility data published by the European committee on antimicrobial susceptibility testing.
abstract: Analysis of 163 disc diffusion data sets, 115 for bacterial species groups and 48 for types strains, published by EUCAST, was used to optimize the setting of the parameters of a standardized protocol for normalized resistance interpretation of these data. The standard deviations of the normalized distributions of these data sets, calculated using this standardized protocol, were shown to be independent of the means of their respective distributions. These standard deviations could, therefore, be used as a metric to quantify the precision of disc diffusion data sets. The median value of the standard deviations for 115 EUCAST data sets produced in multiple laboratory studies of bacterial species groups was 2.3 mm and that for the 48 EUCAST data sets produced in multiple laboratory studies of type strains was 1.5 mm. It is argued that this standardized method for estimating the precision of disc diffusion data provides a tool by which individual laboratories can assess the quality of the disc diffusion data they produce.
authors.affiliation: Department of Microbiology, School of Natural Sciences, National University of Ireland, Galway, Ireland.
authors.forename: Peter
authors.initials: P
authors.lastname: Smith
authors.forename: Göran
authors.initials: G
authors.lastname: Kronvall
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D000890:Anti-Infective Agents / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects*; D008826:Microbial Sensitivity Tests / Q000379:methods*; D012015:Reference Standards
chemical_list: D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents
keywords: Antibiotic; disc diffusion; normalized resistance interpretation; precision; quality control; susceptibility testing