IJHG

official impact factor 2.34

Open Access Methodology

Lumping or splitting: seeking the preferred areal unit for health geography studies

David I Gregorio1*, Laurie M DeChello1, Holly Samociuk1 and Martin Kulldorff2

Author Affiliations

1 Department of Community Medicine & Health Care, University of Connecticut School of Medicine, 263 Farmington Ave., Farmington, CT, 06030-6205, USA

2 Department of Ambulatory Care and Prevention, Harvard Medical School and Harvard Pilgrim Health Care, 133 Brookline Ave, Boston, MA, 02215, USA

For all author emails, please log on.

International Journal of Health Geographics 2005, 4:6 doi:10.1186/1476-072X-4-6

Published: 23 March 2005

Abstract

Background

Findings are compared on geographic variation of incident and late-stage cancers across Connecticut using different areal units for analysis.

Results

Few differences in results were found for analyses across areal units. Global clustering of incident prostate and breast cancer cases was apparent regardless of the level of geography used. The test for local clustering found approximately the same locales, populations at risk and estimated effects. However, some discrepancies were uncovered.

Conclusion

In the absence of conditions calling for surveillance of small area cancer clusters ('hot spots'), the rationale for accepting the burdens of preparing data at levels of geography finer than the census tract may not be compelling.