A Case-Control Study of Sociodemographic and Geographic Characteristics of 335 Children With Eosinophilic Esophagitis  James P. Franciosi, Vicky Tam, Chris A. Liacouras, Jonathan M. Spergel  Clinical Gastroenterology and Hepatology  Volume 7, Issue 4, Pages 415-419 (April 2009) DOI: 10.1016/j.cgh.2008.10.006 Copyright © 2009 AGA Institute Terms and Conditions

Figure 1 EE cohort within the 9-county greater Philadelphia area. Geographically, the greater Philadelphia area is defined as Philadelphia, Bucks, Chester, Delaware, Montgomery, Burlington, Camden, Gloucester, and Mercer Counties. Philadelphia and Camden cities were defined as urban (shaded region), and the remaining 7 counties in addition to the remainder of Camden county were defined as suburban on the basis of incidence density sampling. Within the greater Philadelphia area, EE subject and 2000 U.S. census data were compared in terms of Caucasian race, male sex, MHV of 2000 U.S. census block groups, MHHI of 2000 U.S. census block groups, and household college education of 2000 U.S. census block groups. Clinical Gastroenterology and Hepatology 2009 7, 415-419DOI: (10.1016/j.cgh.2008.10.006) Copyright © 2009 AGA Institute Terms and Conditions

Figure 2 EE cohort geographic clustering. A geographic model of our EE cohort block groups in the 9-county greater Philadelphia area, with the shaded areas representing clustering of EE subjects. Clustering was determined by using the NNI, where values of <1.0 represent significant geographic clustering. Areas of first and second order clustering are illustrated and represent hierarchical grouping of geographic points (address data) on the basis of spatial proximity. There was more clustering in the EE cohort than would be expected by chance alone in the greater Philadelphia region (NNI, 0.8037; P < .001). Clinical Gastroenterology and Hepatology 2009 7, 415-419DOI: (10.1016/j.cgh.2008.10.006) Copyright © 2009 AGA Institute Terms and Conditions