Examination of racial disparities in comorbidities among five-year breast cancer survivors in South Carolina

Background

In South Carolina, breast cancer is the most commonly diagnosed cancer among women, regardless of race, accounting for 32% of all female cancer cases. South Carolina experiences significant disparities in breast cancer mortality between African and European American women. These differences are exacerbated by the presence of comorbidities.

Methods

This retrospective cohort study examines breast cancer incidence and comorbidities among Medicaid recipients in South Carolina from 1995-2005. Medicaid claims data was chosen to control for insurance status and includes demographic variables such as race, age, county of residence, and mortality. Data on comorbidities and breast cancer were collected using the ICD-9 codes. Logistic regression was used to determine whether the independent variables of interest are predictors of five-year survival and chi-square analysis was used to compare differences in comorbidity on five-year survival.

Results

Preliminary analysis suggests that significant racial differences in five-year survival exist. These differences can be partially explained by the presence, severity, treatment and maintenance of comorbidities. We expect significant differences in comorbidity status between African and European American women and predict their effect on five-year survival differences. Prevalent comorbidities and their impact on five-year breast cancer survival indicated by the Charlson/Tammemagi Index were discussed in this study. A better understanding of how comorbid illness affects stage of cancer sheds light on racial disparities in breast cancer survival, and may lead to the development of policies to address the issues of health care delivery on quality.