An exploratory spatial data analysis of low birth weight prevalence in Georgia

Low birth weight (LBW), defined as a live birth weighing less than 2500 g, is a significant public health problem in the United States, but the complex nature of the etiology of this problem is not fully understood. Moreover, significant disparities in LBW prevalence are well documented among certain populations, particularly in minority and underserved communities. The identification of spatial patterns of LBW prevalence is a critical first step in a more complete understanding of the epidemiology of this public health challenge and these techniques are instrumental in designing valid observational and analytical studies to more fully study the problem. This paper examines the spatial patterns of LBW prevalence, as well as the presence of spatial clusters in the State of Georgia at both the county and census tract levels. Unadjusted and empirical Bayes smoothed LBW rates were mapped to visualize the spatial variation of LBW rates, and the Moran's I statistic and the Local Indicator of Spatial Association (LISA) statistic were computed to assess the degree of spatial dependence in the LBW rates. Results revealed marked geographical variation in LBW prevalence in Georgia in 2000. In addition, these data validate the significant disparity (two-fold difference) between white and black racial subgroups as documented in the literature. Trends associated with positive and negative spatial autocorrelations illustrated variation with respect to race. Limitations of data and methods, as well as plans for utility of the results of this study for further investigation were discussed. (C) 2011 Elsevier Ltd. All rights reserved.