College of Veterinary Medicine, Michigan State University, E. Lansing, MI 48824, United States.
Prev Vet Med. 2010 May 1;94(3-4):264-71. doi: 10.1016/j.prevetmed.2010.01.007. Epub 2010 Feb 2.
The Veterinary Medical Database (VMDB) is a summary of veterinary medical records from North American veterinary schools, and is a potential source of disease surveillance information for companion animals. A retrospective record search from four U.S. university veterinary teaching hospitals was used to calculate crude disease rates. Our objectives were to evaluate the utility of the database for disease surveillance purposes by comparing the utility of two methodologies for creating disease categories, and to evaluate the database for evidence of referral bias. Summaries of the medical records from November 2006 to October 2007 for 9577 dogs and 4445 cats were retrieved from VMDB for all canines and felines treated at Kansas State University, Colorado State University, Purdue University and Ohio State University. Disease frequency, computed as apparent period-prevalence and as the percentage of veterinary visits, was compiled for 30 disease categories that were formulated by one of two methods. To assess the possible impact of referral bias, disease rates were compared between animals residing in zip codes within 5 miles of the hospitals (zone 1) and those animals living at more distant locations (zone 2). When compared to zone 1 animals, disease conditions commonly associated with primary veterinary care were reduced by 29-76% within zone 2, and selected diseases generally associated with more specialized care were increased from 46 to 80% among zone 2 animals. The major differences in disease prevalence seen between zones suggests that substantial referral bias may exist, and that adjustment on the basis of geographical proximity to the university teaching hospitals may be useful in reducing this type of selection bias in the VMDB, thereby improve the accuracy of prevalence estimates and enhancing the utility of this database for purposes of disease surveillance.
兽医医学数据库（VMDB）是北美兽医学校兽医病历的摘要，是伴侣动物疾病监测信息的潜在来源。我们使用来自美国四所大学兽医教学医院的回顾性病历检索来计算粗发病率。我们的目标是通过比较两种创建疾病类别方法的效用来评估该数据库在疾病监测中的效用，并评估该数据库是否存在转诊偏倚的证据。从 VMDB 中检索了 2006 年 11 月至 2007 年 10 月期间在堪萨斯州立大学、科罗拉多州立大学、普渡大学和俄亥俄州立大学接受治疗的所有犬类和猫类的医疗记录摘要。为 30 种疾病类别编制了疾病频率，计算方法为明显的时期流行率和兽医就诊的百分比。这 30 种疾病类别是通过两种方法中的一种制定的。为了评估转诊偏倚的可能影响，比较了居住在距离医院 5 英里以内的邮政编码（第 1 区）的动物与居住在更远位置的动物（第 2 区）之间的疾病发生率。与第 1 区动物相比，第 2 区动物中与初级兽医护理相关的常见疾病减少了 29-76%，而与更专门护理相关的某些疾病则从第 2 区动物的 46%增加到 80%。第 1 区和第 2 区之间疾病流行率的主要差异表明，可能存在大量转诊偏倚，并且基于与大学教学医院的地理接近程度进行调整可能有助于减少 VMDB 中的这种选择偏倚，从而提高流行率估计的准确性，并增强该数据库在疾病监测中的效用。
