Low birth weight (LBW), defined as a live birth weighing less than 2,500 grams, is a prevalent condition in the United States and is a significant predictor of infant mortality. The 2004 LBW rate in the country was reported to be 8.1%, a 16% increase since 1990. In addition, LBW births are at elevated risk of experiencing significant developmental problems including respiratory distress, brain hemorrhage, heart problems, and intestinal abnormalities. Although genetics may be linked to an increased risk of LBW, this condition is strongly associated with many characteristics including socioeconomic (eg- lack of access to health care), behavioral (eg – smoking; nutrition), and demographic (eg – mother’s age; race) factors. In Georgia, the unadjusted LBW rate was 9.6% in 2006. When data are controlled for race, the risk for a LBW birth is two times greater among African-Americans (14.4%) compared to whites (7.1%). Moreover, considerable spatial variation exists when examining rates for specific counties in Georgia. In fact, LBWW rates may exceed 25% for African American mothers and 15% for white mothers in certain counties throughout the state. A thorough understanding of the geographic variation, or spatial variability, is then a fundamental requisite for health program planning and control, and for establishing baseline data for subsequent research protocols.

The specific intent of this pilot project is to map and identify significant spatial clusters of LBW cases in Georgia Public Health District 9-1 and 9-2 which includes 24 contiguous counties in southeast Georgia in 2000. First LBW incidences will be mapped using three methods, raw density, locally weighted averages, and empirical Bayes smoothing. Second, spatial patterns of LBW incidences will be analyzed and interpreted using two area-based spatial clustering methods in a Geographic Information System (GIS) environment, Anselin’s Local Indicator of Spatial Association (LISA) and Rogerson’s R Statistic. All the mapping and analyses will be carried in both census tract and zip code area levels and for the total population, African Americans and whites. Finally, the mapping and analytical results will be compared and interpreted.

It is anticipated that this pilot project will lead to a more comprehensive study of the epidemiology of LBW in the entire state of Georgia and at a longer temporal scale. Results gleaned from this preliminary study will also be valuable for other researchers to design more redefined observational studies.