Apley Michael D, Schrag Nora F D, Amrine David E, Lubbers Brian V, Singer Randall S
Department of Clinical Sciences, College of Veterinary Medicine, Kansas State University, Manhattan, KS, United States.
Livestock Veterinary Resources, LLC, Olsburg, KS, United States.
Front Vet Sci. 2023 Jan 4;9:1056476. doi: 10.3389/fvets.2022.1056476. eCollection 2022.
In order to accurately portray antimicrobial use in food animals, the need for standardized metrics, and an understanding of the characteristics of different metrics, has long been recognized. Fourteen U.S. feedyards were used to evaluate the effects of using centralized constants such as defined daily dose (DDD) and defined course dose (DCD) applied to the weight of medically important antimicrobials by class (mg) as opposed to using electronic individual animal treatment records and lot level in-feed antimicrobial records obtained from the same population. Three numerators were calculated directly from recorded data for each drug product: the number of antimicrobial regimens associated with indication (Reg), milligrams of drug administered per regimen (mg), and calendar days of administration for each regimen (CDoA). There were four use indications to which numerators were assigned: liver abscess control (LAC), bovine respiratory disease (BRD), lameness (lame), or all other indications combined (other). Three denominators were also calculated directly from the data, these being the number of days animals were present (head days), number of cattle received (head in), and kilograms of live weight sold (kg-LW). Numerators and denominators were calculated at the lot level. The use of DDD or DCD was explored to determine how their use would affect interpretation of comparisons between lots or feedyards. At the lot level across both study years, the lot estimate of nDDD differed from the CDoA value by >25% in 49.2% of the lots. The number of Defined Course Doses (nDCD) was then compared to the number of Regimens (Reg). Comparing nDCD to Reg at the lot level across both study years, the lot estimate of nDCD differed from the Reg value by >25% in 46.4% of lots. Both year and metric were also shown to affect numerical feedyard ranking by antimicrobial use according to seven different metrics. The analysis reported here adds to the body of literature reporting substantial effects of metric choice on the conclusions drawn from comparing antimicrobial use across multiple production sites.
为了准确描述食用动物中抗菌药物的使用情况，人们早就认识到需要标准化的指标，以及了解不同指标的特点。在美国，选取了14个饲养场来评估使用集中常量（如限定日剂量（DDD）和限定疗程剂量（DCD），按类别（毫克）应用于重要医用抗菌药物的重量）与使用从同一群体获得的电子个体动物治疗记录及批次水平的饲料中抗菌药物记录相比所产生的影响。针对每种药品，直接根据记录数据计算了三个分子：与适应症相关的抗菌治疗方案数量（Reg）、每个治疗方案施用的药物毫克数（mg）以及每个治疗方案的给药日历天数（CDoA）。分子被分配到四种使用适应症：肝脓肿控制（LAC）、牛呼吸道疾病（BRD）、跛行（lame）或所有其他合并适应症（other）。还直接根据数据计算了三个分母，分别是动物在场天数（头日数）、接收的牛数量（进牛头数）以及出售的活体重千克数（kg-LW）。分子和分母在批次水平上进行计算。研究了DDD或DCD的使用情况，以确定它们的使用会如何影响不同批次或饲养场之间比较结果的解读。在两个研究年份的批次水平上，49.2%的批次中限定日剂量（nDDD）的批次估计值与CDoA值相差超过25%。然后将限定疗程剂量数量（nDCD）与治疗方案数量（Reg）进行比较。在两个研究年份的批次水平上比较nDCD和Reg，46.4%的批次中nDCD的批次估计值与Reg值相差超过25%。研究还表明，年份和指标都会影响根据七种不同指标得出的饲养场抗菌药物使用数值排名。此处报告的分析补充了文献资料，表明指标选择对比较多个生产地点抗菌药物使用得出的结论有重大影响。
