Ann Clin Microbiol 2025;29(2):7. Evaluating the adequacy of intervals for repeat antimicrobial susceptibility testing

Table 2. Essential and categorical agreement for specific antimicrobials tested against paired Pseudomonas aeruginosa isolates from the same patient on the same day (n = 17,339)
AntimicrobialsEssential agreement, % (95% CI)a)Categorical agreement, % (95% CI)b)
Amikacin68.3 (65.9, 70.7)79.0 (76.9, 81.1)
Aztreonam64.0 (61.6, 66.4)54.3 (51.9, 56.7)
Ceftazidime59.6 (57.2, 62.0)55.8 (53.4, 58.2)
Ciprofloxacin82.6 (80.5, 84.7)75.2 (72.8, 77.6)
Colistin84.4 (82.4, 86.5)98.8 (98.1, 99.4)
Cefepime64.4 (62.1, 66.7)60.5 (58.1, 62.8)
Gentamicin74.7 (72.5, 76.9)71.1 (68.8, 73.4)
Imipenem78.1 (75.9, 80.4)78.4 (76.1, 80.6)
Levofloxacin80.7 (77.9, 83.4)78.1 (75.3, 81.0)
Meropenem73.9 (71.6, 76.2)75.1 (72.9, 77.4)
Piperacillin70.7 (68.4, 73.0)60.2 (57.7, 62.6)
Piperacillin-tazobactam68.4 (65.9, 70.9)63.8 (61.2, 66.4)

a) Essential Agreement: Two isolates with the same identification from the same patient isolated on the same day with a MIC that is within 1 doubling-dilution in every tested antibiotic.Essential Agreement: Two isolates with the same identification from the same patient isolated on the same day with a MIC that is within 1 doubling-dilution in every tested antibiotic.
b) Categorical Agreement: Two isolates with the same identification from the same patient isolated on the same day that yielded the same categorical interpretation in every tested antibiotic.
Abbreviation: CI, confidence interval.