On the specification of prior distributions for variance components in disease mapping models

Autor: Enrico Fabrizi, Fedele Greco, Carlo Trivisano
Jazyk: angličtina
Rok vydání: 2016
Předmět:
Zdroj: Statistica, Vol 76, Iss 1, Pp 93-111 (2016)
Druh dokumentu: article
ISSN: 0390-590X
1973-2201
DOI: 10.6092/issn.1973-2201/6319
Popis: In this paper, we consider the problem of specifying priors for the variance components in the Bayesian analysis of the Besag-York-Mollié model, a model that is popular among epidemiologists for disease mapping. The model encompasses two sets of random effects: one spatially structured to model spatial autocorrelation and the other spatially unstructured to describe residual heterogeneity. In this model, prior specification for variance components is an important problem because these priors maintain their influence on the posterior distributions of relative risks when mapping rare diseases. We propose using generalised inverse Gaussian priors, a broad class of distributions that includes many distributions commonly used as priors in this context, such as inverse gammas. We discuss the prior parameter choice with the aim of balancing the prior weight of the two sets of random effects on total variation and controlling the amount of shrinkage. The suggested prior specification strategy is compared to popular alternatives using a simulation exercise and applications to real data sets.
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