Mapping malaria risk in West Africa using a Bayesian nonparametric non-stationary model
Mapping malaria risk in West Africa using a Bayesian nonparametric non-stationary model
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DOI:
10.1016/j.csda.2009.02.022
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发表时间:
2009-07-01
影响因子:
1.8
通讯作者:
Smith, T.
中科院分区:
文献类型:
--
作者:
Gosoniu, L.;Vounatsou, P.;Smith, T.
Malaria transmission is highly influenced by environmental and climatic conditions but their effects are often not linear. The climate-malaria relation is unlikely to be the same over large areas covered by different agro-ecological zones. Similarly, spatial correlation in malaria transmission arisen mainly due to spatially structured covariates (environmental and human made factors), could vary across the agro-ecological zones, introducing non-stationarity. Malaria prevalence data from West Africa extracted from the "Mapping Malaria Risk in Africa" database were analyzed to produce regional parasitaemia risk maps. A non-stationary geostatistical model was developed assuming that the underlying spatial process is a mixture of separate stationary processes within each zone. Non-linearity in the environmental effects was modeled by separate P-splines in each agro-ecological zone. The model allows smoothing at the borders between the zones. The P-splines approach has better predictive ability than categorizing the covariates as an alternative of modeling non-linearity. Model fit and prediction was handled within a Bayesian framework, using Markov chain Monte Carlo (MCMC) simulations. (C) 2009 Elsevier B.V. All rights reserved.