THE SPATIAL RELATIONSHIP BETWEEN INFANT-MORTALITY AND BIRTH-DEFECT RATES IN A US CITY

The spatial patterns of infant mortality and birth defect rates in the Des Moines, Iowa, urban region are described as a contoured surface b ased on the punctual kriging of address-matched vital statistics recor ds from The Iowa Department of Public Health. Areas defined as having high rates are shown to be sensitive to the size of the spatial filter ing units. There is no correlation between infant mortality and birth defect rates in the region. The significance of areas with high rates is determined by a Monte Carlo simulation procedure, One area of high infant mortality is found in the region, which contrasts with many sma ller areas with high birth defect rates in the region. The observed bi rth defect rate pattern is consistent with the hypothesis that each bi rth was equally likely to result in a birth defect, while the infant m ortality pattern is unlikely to be the result of such an equal likelih ood process.