Abstract:
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Spatial distributions find applications in various fields, such as public health, biology, ecology, geography, economics or sociology. The DAC statistic is the difference between the empirical cumulative distribution of cases and that of non-cases at a particular point. Simulations indicated that the location of the maximum DAC statistic is not unique. Previous studies attempting to use the DAC statistic to suggest or even predict occurrences of low birthweight clusters faced various problems, such as the discrete nature of sample data or software limitations. This study uses the longitude and latitude as the coordinates of the homes of mothers in Spartanburg County, SC who gave birth to their babies in 1989 or 1990, and the DAC statistic in conjunction with various kriging approaches. For the particular data set used in this study, SAS yielded inconclusive results. The results obtained using ArcGIS confirm previous findings suggesting low birthweight clusters located in Spartanburg, Chesnee, and possibly Inman and Greer. Therefore, the DAC statistic should be used with caution, but its usefulness as a set of spatial descriptive statistic is not diminished in the least.
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