Area-to-Area Poisson Kriging Analysis of Mapping of County-Level Esophageal Cancer Incidence Rates in Iran


Background: Esophagus cancer, the third most common gastrointestinal cancer overall, demonstrates highincidence in parts of Iran. The counties of Iran vary in size, shape and population size. The aim of this studywas to account for spatial support with Area-to-Area (ATA) Poisson Kriging to increase precision of parameterestimates and yield correct variance and create maps of disease rates. Materials and
Methods: This studyinvolved application/ecology methodology, illustrated using esophagus cancer data recorded by the Ministryof Health and Medical Education (in the Non-infectious Diseases Management Center) of Iran. The analysisfocused on the 336 counties over the years 2003-2007. ATA was used for estimating the parameters of the mapwith SpaceStat and ArcGIS9.3 software for analysing the data and drawing maps.
Results: Northern counties ofIran have high risk estimation. The ATA Poisson Kriging approach yielded variance increase in large sparselypopulated counties. So, central counties had the most prediction variance.
Conclusions: The ATAPoisson krigingapproach is recommended for estimating parameters of disease mapping since this method accounts for spatialsupport and patterns in irregular spatial areas. The results demonstrate that the counties in provinces Ardebil,Mazandaran and Kordestan have higher risk than other counties.