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Wednesday, April 29, 2009

Hierarchical additive modeling of nonlinear association with spatial correlations - An application to relate alcohol outlet density and neighborhood assault rates
Statistics in Medicine Published Online: 28 Apr 2009


We propose a hierarchical additive model, where the nonlinear correlations and the complex interaction effects are modeled using the multiple additive regression trees and the residual spatial association in the assault rates that cannot be explained in the model are smoothed using a conditional autoregressive (CAR) method.
We develop a two-stage algorithm that connects the nonparametric trees with CAR to look for important covariates associated with the assault rates, while taking into account the spatial association of assault rates in adjacent census tracts.
The proposed method is applied to the Los Angeles assault data (1990-1999). To assess the efficiency of the method, the results are compared with those obtained from a hierarchical linear model.
Requerst Reprint E-Mail: qyu@lsuhsc.edu
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