Numerous factors are believed to be behind the spatial distribution of birth defects. Contextual factors which also cluster in space, such as environmental exposures, have been associated with the development of birth defects. Birth defects also appear to occur more frequently among children born to women of lower socioeconomic status. Clustering may therefore be due to compositional effects, or the fact that individual or family-level risk factors that contribute to birth defects may cluster in an area to produce larger area-level effects.
This study explored which environmental, social and economic factors are most important in explaining the geographic variation of two birth defects in North Carolina: orofacial clefts and gastroschisis. This study used the disease ecology framework and spatial methodologies – spatial statistics, Geographic Information Systems, and hydrological modeling – to explore the geographic distribution of gastroschisis in North Carolina and suggest possible socioeconomic and environmental factors that may contribute to the disease. Study data are derived from North Carolina’s population-based birth defects registry and linked birth files. Specific questions addressed in this study include: 1) Do significant geographic clusters of birth defects exist in North Carolina and, if so, what are the approximate locations of these clusters? 2) What area-level socioeconomic characteristics are related to birth defect outcomes? 3) Do clusters suggest the presence of point-source environmental pollutants? 4) What can this tell us about possible causes of the disease?
This study not only examined the etiology of birth defects by also explored the concept of “neighborhood” and developed empirical methods for defining the spatial scale at which area-level factors may influence health.
Moving Neighborhood and Health Research Forward: Using Geographic Methods to Examine how Spatial Scale and Mobility Affect Neighborhood Effects on Health. 2012. Ann Assoc Am Geogr.
Socioeconomic Context and Gastroschisis: Exploring Associations at Various Geographic Scales. 2011. Soc Sci Med.
Tracing drinking water to its source: an ecological study of the relationship between textile mills and gastroschisis in North Carolina. 2010. Health Place.
Evidence of Localized Clustering of Gastroschisis in North Carolina, 1999-2004. 2009. Soc Sci Med.
National Science Foundation Doctoral Dissertation Research Improvement grant (#0825511)
National Science Foundation’s IGERT Predoctoral Fellowship Program (#DGE-0333193) at the Carolina Population Center at the University of North Carolina at Chapel Hill.