Evaluation of spatial filters to create smoothed maps of health data

Spatial filters have been used as an easy and intuitive way to create smoot hed disease maps. Birth weight data from New York State for 1994 and 1995 a re used to compare the traditional filter type of fixed geographical size w ith a filter size of constant or nearly constant population size. The latte r are more appropriate for mapping disease in geographic areas with widely varying population density, such as New York State. Issues such as the choi ce of population size for the filter, the scale of smoothing, the ability t o detect true spatial variation and the ability to smooth over random spati al noise are evaluated and discussed. Copyright (C) 2000 John Wiley & Sons, Ltd.