Sargeant J M, Kelton D F, O'Connor A M
Centre for Public Health and Zoonoses, University of Guelph, Guelph, ON, Canada; Department of Population Medicine, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada.
Zoonoses Public Health. 2014 Jun;61 Suppl 1:10-7. doi: 10.1111/zph.12127.
This article is the second article in a series of six focusing on systematic reviews in animal agriculture and veterinary medicine. This article addresses the strengths and limitations of study designs commonly used in animal agriculture and veterinary research to assess interventions (preventive or therapeutic treatments) and discusses the appropriateness of their use in systematic reviews of interventions. Different study designs provide different evidentiary value for addressing questions about the efficacy of interventions. Experimental study designs range from in vivo proof of concept experiments to randomized controlled trials (RCTs) under real-world conditions. The key characteristic of experimental design in intervention studies is that the investigator controls the allocation of individuals or groups to different intervention strategies. The RCT is considered the gold standard for evaluating the efficacy of interventions and, if there are well-executed RCTs available for inclusion in a systematic review, that review may be restricted to only this design. In some instances, RCTs may not be feasible or ethical to perform, and there are fewer RCTs published in the veterinary literature compared to the human healthcare literature. Therefore, observational study designs, where the investigator does not control intervention allocation, may provide the only available evidence of intervention efficacy. While observational studies tend to be relevant to real-world use of an intervention, they are more prone to bias. Human healthcare researchers use a pyramid of evidence diagram to describe the evidentiary value of different study designs for assessing interventions. Modifications for veterinary medicine are presented in this article.
本文是关于动物农业和兽医学系统评价系列六篇文章中的第二篇。本文探讨了动物农业和兽医研究中常用于评估干预措施（预防性或治疗性治疗）的研究设计的优势和局限性，并讨论了其在干预措施系统评价中的适用性。不同的研究设计在解决干预措施疗效问题时提供不同的证据价值。实验性研究设计范围从体内概念验证实验到现实世界条件下的随机对照试验（RCT）。干预研究中实验设计的关键特征是研究者控制个体或组分配到不同的干预策略。RCT被认为是评估干预措施疗效的金标准，如果有执行良好的RCT可纳入系统评价，那么该评价可能仅限于此设计。在某些情况下，进行RCT可能不可行或不符合伦理，并且与人类医疗文献相比，兽医文献中发表的RCT较少。因此，研究者不控制干预分配的观察性研究设计可能提供干预措施疗效的唯一可用证据。虽然观察性研究往往与干预措施的实际应用相关，但它们更容易产生偏差。人类医疗研究人员使用证据金字塔图来描述不同研究设计在评估干预措施时的证据价值。本文介绍了针对兽医学的修改。
