The incidence rate is indirectly standardized by age and sex and smoothed using adaptive filter density estimation. Each rate is based on the closest 50 expected cases on a grid that is densified in urban areas to increase geographic detail. Red areas indicate higher rates than expected and blue areas indicate lower rates than expected, given the statewide incidence rate. The highest and lowest third of the state are colored, while no color is shown for the middle third.
Data Sources: Cancer incidence data from the State Health Registry of Iowa. 1:100,000 Digital Raster Graphic from the Iowa Geographic Image Map Server hosted by Iowa State University. County borders, incorporated area locations, and interstate highways from the Natural Resources GIS Library hosted by the Iowa Department of Natural Resources and the US Geological Survey.
Created by Kirsten Beyer, Zunqiu Chen, David Haynes, Gerard Rushton, and Chetan Tiwari at the University of Iowa Department of Geography, July 2008.