Raboisson Didier, Ferchiou Ahmed, Pinior Beate, Gautier Thomas, Sans Pierre, Lhermie Guillaume
IHAP, Université de Toulouse, INRAE, ENVT, Toulouse, France.
Food Technology and Veterinary Public Health, Institute of Food Safety, University of Veterinary Medicine Vienna, Vienna, Austria.
Front Vet Sci. 2020 Mar 18;7:149. doi: 10.3389/fvets.2020.00149. eCollection 2020.
The literature contains an extensive panel of studies focusing on the costs of animal diseases. The losses of an agriculture holding can be influenced by many factors since farming is a complex system and diseases are closely interrelated. Meta-analysis can be used to detect effects (i.e., change in clinical mastitis losses here) across studies and to identify factors that may influence those effects. This includes the external validity of the published study results with regard to the input parameters and the internal validity of the study, particularly how other diseases related to the target disease were accounted for. Mixed-effect meta-regressions were performed to estimate the mean clinical mastitis losses per case across the literature and to elucidate to what extent clinical mastitis losses are influenced by (i) general factors, such as etiology; (ii) the types of losses that contribute to the total mastitis losses; and (iii) prices. In total, 82 observations from nine studies were included in the meta-analysis to assess mean clinical mastitis losses per case. The multivariate meta-regression showed that etiology significantly influenced the clinical mastitis loss per case. The mean loss was determined to be €224 per case for all published etiologies. In detail, mean losses equalled €457 and €101 per case of clinical mastitis due to gram-negative and gram-positive bacteria, respectively, and €428 and €74 per case of clinical mastitis due to and , respectively. Additionally, the mean loss obtained depended on whether diagnostic costs and reduced feed intake in cases of mastitis were included in the clinical mastitis loss calculation. The monetary values of labor cost, drug cost and culling cost, as well as treatment price (all included), significantly influenced the clinical mastitis losses per case. All other tested moderators were not associated with mastitis losses, highlighting the need for more standardized economic studies, for both methods and ways results are presented, and suggesting that the mastitis losses assessed in the literature cannot be extrapolated (limited external validity). Although meta-analyses are useful to overview the burden of diseases across studies, their ability to summarize extensive literature with various economic assessments is limited. These limitations in loss assessments also suggest the need to focus on management strategies rather than on pure monetary estimations of disease costs, at least for production diseases at the farm level.
文献中有大量关于动物疾病成本的研究。由于农业生产是一个复杂的系统，且疾病之间相互关联紧密，农业经营的损失可能受到多种因素影响。荟萃分析可用于检测各项研究的效应（即此处临床乳腺炎损失的变化），并识别可能影响这些效应的因素。这包括已发表研究结果在输入参数方面的外部有效性以及研究的内部有效性，特别是与目标疾病相关的其他疾病是如何被考虑在内的。进行了混合效应元回归分析，以估计文献中每例临床乳腺炎的平均损失，并阐明临床乳腺炎损失在多大程度上受到以下因素的影响：（i）一般因素，如病因；（ii）导致总乳腺炎损失的损失类型；以及（iii）价格。总共，来自9项研究的82个观测值被纳入荟萃分析，以评估每例临床乳腺炎的平均损失。多元元回归分析表明，病因显著影响每例临床乳腺炎的损失。所有已发表病因的平均损失确定为每例224欧元。具体而言，革兰氏阴性菌和革兰氏阳性菌引起的临床乳腺炎每例平均损失分别为457欧元和101欧元，[此处原文缺失两种病因，无法准确翻译]引起的临床乳腺炎每例平均损失分别为428欧元和74欧元。此外，所获得的平均损失取决于临床乳腺炎损失计算中是否包括诊断成本和乳腺炎病例中减少的采食量。劳动力成本、药物成本和扑杀成本的货币价值以及治疗价格（全部包括在内），均对每例临床乳腺炎损失有显著影响。所有其他测试的调节因素均与乳腺炎损失无关，这凸显了对经济研究在方法和结果呈现方式上进行更标准化的必要性，并表明文献中评估的乳腺炎损失无法外推（外部有效性有限）。尽管荟萃分析有助于概述各项研究中疾病的负担，但其总结包含各种经济评估的大量文献的能力是有限的。损失评估中的这些局限性还表明，至少对于农场层面的生产性疾病，需要关注管理策略而非单纯对疾病成本进行货币估计。
