title: Statistical criteria for selecting quality control limits for broth microdilution susceptibility tests with 39 different antimicrobial agents. Collaborative Antimicrobial Susceptibility Testing Group.
abstract: Multilaboratory studies have been carried out to establish quality control limits for broth microdilution susceptibility tests with 39 different antimicrobial agents and four different control strains. For each drug-microorganism combination, 100 MIC values were recorded (20 from each of five laboratories). An acceptable range of MICs was defined as values that included greater than 95% of those 100 MICs. In a series of consecutive tests, less than or equal to 5% of the MIC values might be expected to be one doubling dilution interval above or below the limits defined in that way: at least 95% of those MIC determinations should be within the narrow control limits. The 39 antimicrobial agents provided 111 drug-microorganism combinations for which usable quality control limits could be defined. The greater than 95% rule yielded a narrow range (including only two dilution steps) with 58 of the 111 control limits, and 53 control limits permitted a more traditional three-dilution step range of MICs.
authors.affiliation: Clinical Microbiology Institute, Tualatin, Oregon.
authors.forename: A L
authors.initials: AL
authors.lastname: Barry
authors.forename: P C
authors.initials: PC
authors.lastname: Fuchs
authors.forename: R N
authors.initials: RN
authors.lastname: Jones
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects*; D008826:Microbial Sensitivity Tests / Q000592:standards*; D011786:Quality Control
chemical_list: D000900:Anti-Bacterial Agents