Characterizing antimicrobial use in animal populations is critical for purposes of antimicrobial stewardship. While dose-based metrics such as the animal daily dose (ADD) are typically used for such purposes, duration of therapy is emerging as a critical and more intuitive metric. In theory, the number of ADDs should approximate the number of days of therapy (DOTs), but no studies have examined whether this is the case. The objective of this study was to compare antimicrobial ADDs with antimicrobial DOTs in three populations: canine patients, large animal hospital patients, and dairy herds. In the first two populations, dose-based metrics were calculated using administrative hospital records while duration-based metrics were ascertained from manual chart review of individual animals. In the dairy herds, both metrics were obtained via farmer self-report. We found that the correlation between the number of ADDs and DOTs was poor for hospital patients (Lin correlation coefficients of 0.16 and 0.18 for small and large animals, respectively) and that there were often large differences between the two metrics for all populations, with ADDs most often overestimating the number of DOTs. While the median (IQR) differences between the number of DOTs and ADDs were relatively small (-9.4 (-25.7-(-0.92)), 0.34 (-5.0-4.0), and 0.0 (-18.0-9.0) among canine patients, large animal hospital patients, and dairy herds, respectively), the limits of agreement (-89.4-13.2, -37.7-9.9, and -100.0-53.0, respectively) were likely too large to be acceptable for most investigative purposes. Increased discrepancies between the two metrics were significantly associated with certain animal species (e.g., dogs, small ruminants) and drug classes (e.g., penicillins, cephalosporins, macrolides), decreased animal weight, and increased length of hospital stay. While the number of ADDs can approximate the number of DOTs under certain circumstances, the large limits of agreement between these two measurements suggest that the ADD is generally not a reliable proxy for the duration of therapy.

中文翻译：

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比较具有重要兽医作用的动物的动物每日剂量和治疗天数。

在动物种群中表征抗菌药物的使用对于抗菌药物管理至关重要。虽然通常将基于剂量的度量标准（例如动物日剂量（ADD））用于此类目的，但治疗持续时间正在成为一种关键且更直观的度量标准。从理论上讲，ADD的数量应近似于治疗的天数（DOT），但尚无研究检查这种情况。这项研究的目的是比较三种人群中的抗菌素ADDs和抗菌素DOT：犬类患者，大型动物医院患者和奶牛场。在前两个种群中，使用行政医院记录来计算基于剂量的指标，而通过对各个动物进行手动图表审查确定基于持续时间的指标。在奶牛群中 这两个指标都是通过农民的自我报告获得的。我们发现，住院患者ADD和DOT数量之间的相关性较差（小动物和大动物的Lin相关系数分别为0.16和0.18），并且对于所有人群，ADD的两个指标之间通常存在较大差异最经常高估DOT的数量。尽管犬类患者中DOT和ADD数量之间的中位数（IQR）差异相对较小（-9.4（-25.7-（-0.92）），0.34（-5.0-4.0）和0.0（-18.0-9.0），大型动物医院的患者和奶牛群），协议的限制（分别为-89.4-13.2，-37.7-9.9和-100.0-53.0）可能太大而无法为大多数研究目的所接受。两种指标之间差异的增加与某些动物种类（例如狗，小反刍动物）和药物类别（例如青霉素，头孢菌素，大环内酯类），动物体重减轻和住院时间延长显着相关。尽管在某些情况下ADD的数量可以近似于DOT的数量，但这两个测量值之间的较大一致性限制表明ADD通常不是治疗期间的可靠替代。