Breast cancer screening and incidence in communities with a high proportion of uninsured

Research has not established (1) if breast cancer screening varies by county-level proportion of uninsured or (2) whether county-level-proportion of uninsured correlates with county-level early-stage and late-stage breast cancer incidence.

A multilevel study was conducted to determine if individual-level self-reported breast cancer screening data from the 2000 Behavioral Risk Factor Surveillance System (BRFSS) was associated with county-level-proportion-uninsured data from the 1999-2001 BRFSS. An ecologic study was conducted to determine if county-level proportion of uninsured correlated with incidence of early-stage and late-stage breast cancer using the 1999-2001 BRFSS data from the overlapping counties in the Surveillance, Epidemiology, and End Results (SEER) program. Data were analyzed in 2005.

Women were less likely to be screened (prevalence odds ratio: 0.95; 95% confidence interval=0.93-0.97) with every 5% increasing county-level proportion of uninsured. African-American and Hispanic women who resided in counties with a proportion of uninsured of 9%-19% had higher screening utilization than white non-Hispanic women. The county-level-proportion of uninsured had little effect on screening use among women with household incomes less than $25,000 or greater than $75,000. Screening prevalence decreased with increasing county-level proportion of uninsured among women with intermediate income. The rate of T1 (<2 cm diameter) tumors decreased with increasing county-level proportion of uninsured while controlling for poverty rate; Spearman correlation -0.294.

High county-level proportions of uninsured may lead to lower early-stage breast-cancer incidence through lower screening use among women living in these less-well-insured counties.