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The 130th Annual Meeting of APHA |
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The 130th Annual Meeting of APHA |
Laurel A. Spielberg, MPH, DrPH, School of Public Health, MCP Hahnemann University, 245 N. 15th Street, Mail Stop 660, Philadelphia, PA 19102-1192, 215-762=1379, Spieldrph@aol.com and Suet Tieng Lim, PhD, Department of Health, Montgomery County, 1430 Dekalb Street, P.O. Box 311, Norristown, PA 19401-0311.
Community concerns about elevated disease rates and perceived clusters encourage us to search for investigative methods to validate public perceptions and elucidate causal factors. Recently, the Montgomery County Health Department was asked to investigate breast cancer incidence in a community that appeared to have the highest breast cancer rates in the county. Breast cancer incident cases in the Pennsylvania Cancer Registry, 1985-1997, were geocoded using a GIS, allowing examination of spatial density, distribution, and identification of cases among particular residential subpopulations for both the community of concern and the remaining county. For instance, matching Archdiocese convent addresses on the GIS allowed determining the contribution of convent residents (i.e., nuns), presumed at higher risk for breast cancer due to their nulliparity, to the communityÕs breast cancer experience. Geocoding detected a high rate of geographic misallocation of cases (16%) to this community, which borders three other counties. 91% of misallocated cases correctly belonged to adjacent counties. Similar GIS breast cancer analysis of a comparison border community showed similar misallocation rate (16%), but a different pattern, with misallocated cases belonging elsewhere within our county. Discussion with hospital Tumor Registrars revealed residence designation at one hospital was contributing to the considerable misallocation bias in geographic assignment of cases in the community of concern. GIS analysis of surrounding countiesÕ data allowed capture of all regional breast cancer cases and geographic correction of small area rates. Relative risk of breast cancer in the concerned community compared to the remaining county dropped from 1.40 to 1.17.
Learning Objectives:
Keywords: Geographic Information Systems, Breast Cancer
Presenting author's disclosure statement:
I do not have any significant financial interest/arrangement or affiliation with any organization/institution whose products or services are being discussed in this session.