American Journal of Epidemiology Advance Access published online on December 22, 2008
American Journal of Epidemiology, doi:10.1093/aje/kwn369
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Original Contribution |
The Role of Poverty Rate and Racial Distribution in the Geographic Clustering of Breast Cancer Survival Among Older Women: A Geographic and Multilevel Analysis
Correspondence to Dr. Mario Schootman, Campus Box 8504, Division of Health Behavior Research, Departments of Medicine and Pediatrics, Washington University School of Medicine, 4444 Forest Park Avenue, Saint Louis, MO 63108 (e-mail: mschootm{at}dom.wustl.edu).
Received for publication December 18, 2007. Accepted for publication October 21, 2008.
The authors examined disparities in survival among women aged 66 years or older in association with census-tract-level poverty rate, racial distribution, and individual-level factors, including patient-, treatment-, and tumor-related factors, utilization of medical care, and mammography use. They used linked data from the 1992–1999 Surveillance, Epidemiology, and End Results (SEER) programs, 1991–1999 Medicare claims, and the 1990 US Census. A geographic information system and advanced statistics identified areas of increased or reduced breast cancer survival and possible reasons for geographic variation in survival in 2 of the 5 SEER areas studied. In the Detroit, Michigan, area, one geographic cluster of shorter-than-expected breast cancer survival was identified (hazard ratio (HR) = 1.60). An additional area where survival was longer than expected approached statistical significance (HR = 0.4; P = 0.056). In the Atlanta, Georgia, area, one cluster of shorter- (HR = 1.81) and one cluster of longer-than-expected (HR = 0.72) breast cancer survival were identified. Stage at diagnosis and census-tract poverty (and patient's race in Atlanta) explained the geographic variation in breast cancer survival. No geographic clusters were identified in the 3 other SEER programs. Interventions to reduce late-stage breast cancer, focusing on areas of high poverty and targeting African Americans, may reduce disparities in breast cancer survival in the Detroit and Atlanta areas.
breast neoplasms; cluster analysis; geography; population groups; poverty; survival
Abbreviations: ACSH, ambulatory-care–sensitive hospitalization(s); CI, confidence interval; HR, hazard ratio; ICD-9-CM, International Classification of Diseases, Ninth Revision, Clinical Modification; SEER, Surveillance, Epidemiology, and End Results