Reducing a spatial database to its effective dimensionality for logistic - regression analysis of incidence of livestock disease

Large databases with multiple variables, selected because they are available and might provide an insight into establishing causal relationships, are often difficult to analyse and interpret because of multicollinearity. The objective of this study was to reduce the dimensionality of a multivariable...

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Bibliographic Details
Main Authors: Duchateau, L., Kruska, Russell L., Perry, Brian D.
Format: Journal Article
Language:Inglés
Published: Elsevier 1997
Subjects:
Online Access:https://hdl.handle.net/10568/29499
Description
Summary:Large databases with multiple variables, selected because they are available and might provide an insight into establishing causal relationships, are often difficult to analyse and interpret because of multicollinearity. The objective of this study was to reduce the dimensionality of a multivariable spatial database of Zimbabwe, containing many environmental variables that were collected to predict the distribution of outbreaks of theileriosis (the tick-borne infection of cattle caused by Theileria parva and transmitted by the brown ear tick). Principal-component analysis and varimax rotation of the principal components were first used to select a reduced number of variables. The logistic-regression model was evaluated by appropriate goodness-of-fit-tests.