Chhetri Bimal K, Berke Olaf, Pearl David L, Bienzle Dorothee
Department of Population Medicine, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada N1G 2W1.
Department of Population Medicine, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada N1G 2W1 ; Department of Mathematics and Statistics, University of Guelph, Guelph, ON, Canada N1G 2W1 ; Institute of Biometry, Epidemiology and Information Processing, University of Veterinary Medicine Hannover (Foundation), 30173 Hannover, Germany.
J Vet Med. 2014;2014:424138. doi: 10.1155/2014/424138. Epub 2014 Feb 19.
The knowledge of the spatial distribution feline immunodeficiency virus and feline leukemia virus infections, which are untreatable, can inform on their risk factors and high-risk areas to enhance control. However, when spatial analysis involves aggregated spatial data, results may be influenced by the spatial scale of aggregation, an effect known as the modifiable areal unit problem (MAUP). In this study, area level risk factors for both infections in 28,914 cats tested with ELISA were investigated by multivariable spatial Poisson regression models along with MAUP effect on spatial clustering and cluster detection (for postal codes, counties, and states) by Moran's I test and spatial scan test, respectively. The study results indicate that the significance and magnitude of the association of risk factors with both infections varied with aggregation scale. Further more, Moran's I test only identified spatial clustering at postal code and county levels of aggregation. Similarly, the spatial scan test indicated that the number, size, and location of clusters varied over aggregation scales. In conclusion, the association between infection and area was influenced by the choice of spatial scale and indicates the importance of study design and data analysis with respect to specific research questions.
猫免疫缺陷病毒和猫白血病病毒感染无法治愈，了解其空间分布情况有助于了解其风险因素和高风险区域，从而加强防控。然而，当空间分析涉及聚合空间数据时，结果可能会受到聚合空间尺度的影响，这种效应被称为可变面积单元问题（MAUP）。在本研究中，通过多变量空间泊松回归模型，对28914只接受酶联免疫吸附测定（ELISA）检测的猫的这两种感染的区域层面风险因素进行了调查，并分别通过莫兰指数（Moran's I）检验和空间扫描检验，研究了MAUP对空间聚集和聚集检测（针对邮政编码、县和州）的影响。研究结果表明，风险因素与这两种感染的关联的显著性和强度随聚合尺度而变化。此外，莫兰指数检验仅在邮政编码和县层面的聚合中识别出空间聚集。同样，空间扫描检验表明，聚集的数量、大小和位置随聚合尺度而变化。总之，感染与区域之间的关联受空间尺度选择的影响，这表明针对特定研究问题的研究设计和数据分析很重要。
