Method for Mapping Population-Based Case-Control Studies: An Application Using Generalized Additive Models


Show simple item record Webster, Thomas en_US Vieira, Verónica en_US Weinberg, Janice en_US Aschengrau, Ann en_US 2012-01-11T15:51:16Z 2012-01-11T15:51:16Z 2006 en_US 2006-6-9 en_US
dc.identifier.citation Webster, Thomas, Verónica Vieira, Janice Weinberg, Ann Aschengrau. "Method for mapping population-based case-control studies: an application using generalized additive models" International Journal of Health Geographics 5:26. (2006) en_US
dc.identifier.issn 1476-072X en_US
dc.description.abstract BACKGROUND. Mapping spatial distributions of disease occurrence and risk can serve as a useful tool for identifying exposures of public health concern. Disease registry data are often mapped by town or county of diagnosis and contain limited data on covariates. These maps often possess poor spatial resolution, the potential for spatial confounding, and the inability to consider latency. Population-based case-control studies can provide detailed information on residential history and covariates. RESULTS. Generalized additive models (GAMs) provide a useful framework for mapping point-based epidemiologic data. Smoothing on location while controlling for covariates produces adjusted maps. We generate maps of odds ratios using the entire study area as a reference. We smooth using a locally weighted regression smoother (loess), a method that combines the advantages of nearest neighbor and kernel methods. We choose an optimal degree of smoothing by minimizing Akaike's Information Criterion. We use a deviance-based test to assess the overall importance of location in the model and pointwise permutation tests to locate regions of significantly increased or decreased risk. The method is illustrated with synthetic data and data from a population-based case-control study, using S-Plus and ArcView software. CONCLUSION. Our goal is to develop practical methods for mapping population-based case-control and cohort studies. The method described here performs well for our synthetic data, reproducing important features of the data and adequately controlling the covariate. When applied to the population-based case-control data set, the method suggests spatial confounding and identifies statistically significant areas of increased and decreased odds ratios. en_US
dc.description.sponsorship National Institute of Enviornmental Health (5P42ES007381) en_US
dc.language.iso en en_US
dc.publisher BioMed Central en_US
dc.rights Copyright 2006 Webster et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. en_US
dc.rights.uri en_US
dc.title Method for Mapping Population-Based Case-Control Studies: An Application Using Generalized Additive Models en_US
dc.type article en_US
dc.identifier.doi 10.1186/1476-072X-5-26 en_US
dc.identifier.pubmedid 16764727 en_US
dc.identifier.pmcid 1526437 en_US

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