The critical influence of the intermediate category on interpretation errors in revised EUCAST and CLSI antimicrobial susceptibility testing guidelines
The critical influence of the intermediate category on interpretation errors in revised EUCAST and CLSI antimicrobial susceptibility testing guidelines
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DOI：
10.1111/1469-0691.12090
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发表时间：
2013-02-01
影响因子：
14.2
通讯作者：
Roos, M.
中科院分区：
文献类型：
--
作者：
Hombach, M.;Boettger, E. C.;Roos, M.
错误地将临床分离株归入易感、中间和耐药的解释类别可能会剥夺患者成功的抗菌治疗。重大误差率(ME)和极大误差率(VME)取决于：(1)抗生素药敏试验(AST)方法的精密度/标准差(Sigma)；(2)直径分布；(3)临床断点；(4)中间带的宽度。欧洲AST委员会(EUCAST)已经放弃或减少了几种药物/物种组合的中间区域。本研究重点考察了中级范畴的中断对口译错误率的影响。总共有10341个非重复的临床分离株被纳入研究。药敏试验采用纸片扩散法。对于解释类别边界两侧的直径值，分别计算了错误概率。然后将错误概率应用于所调查的临床分离株的实际数量，并计算出ME和VME的预期比率。应用EUCAST AST指南，在没有中间范围的所有药物/药物组合中，显示出显著的ME/VME比率。在保留中间区的CLSI指南中，几乎所有预期的ME/VME都被取消了。如果野生型和抗性菌株在敏感性分布上没有明显的区分，保留中间带将减少ME和VME的数量。根据直径分布，23 mm的中间区域几乎避免了大多数物种/药物组合的ME/VME。实验室应该了解他们的流行病学环境，以便能够检测单个物种/药物/临床断点组合的问题，并采取措施提高直径测量的精度。
Erroneous assignments of clinical isolates to the interpretative categories susceptible, intermediate and resistant can deprive a patient of successful antimicrobial therapy. The rate of major errors (ME) and very major errors (vME) is dependent on: (i) the precision/standard deviation (sigma) of the antibiotic susceptibility testing (AST) method, (ii) the diameter distributions, (iii) clinical breakpoints, and (iv) the width of the intermediate zone. The European Committee on AST (EUCAST) has abandoned or decreased the intermediate zone for several drug/species combinations. This study focused on the effects of discontinuing the intermediate category on the rate of interpretation errors. In total, 10341 non-duplicate clinical isolates were included in the study. For susceptibility testing the disc diffusion method was used. Error probabilities were calculated separately for diameter values flanking the interpretative category borders. Error probabilities were then applied to the actual numbers of clinical isolates investigated and expected rates of ME and vME were calculated. Applying EUCAST AST guidelines, significant rates of ME/vME were demonstrated for all drug/species combinations without an intermediate range. Virtually all ME/vME expected were eliminated in CLSI guidelines that retained an intermediate zone. If wild-type and resistant isolates are not clearly separated in susceptibility distributions, the retaining of an intermediate zone will decrease the number of ME and vME. An intermediate zone of 23mm avoids almost all ME/vME for most species/drug combinations depending on diameter distributions. Laboratories should know their epidemiology settings to be able to detect problems of individual species/drug/clinical breakpoint combinations and take measures to improve precision of diameter measurements.