Black women receive less mammography even with similar use of primary care.

BACKGROUND: Black women with breast cancer have a decreased 5-year survival rate in comparison with white women, possibly because of less frequent use of mammography. Having a regular provider or source of health care is the most important determinant of mammography use.
OBJECTIVE: To examine whether the difference in mammography use between elderly black women and elderly white women is related to the number of visits made to a primary care physician.
DESIGN: Retrospective review of 1990 Health Care Financing Administration billing files (Medicare part B) from 10 states.
SETTING: Outpatient mammography services in 10 states. PARTICIPANTS: Black women and white women, 65 years of age and older, residing in one of the 10 states. MEASUREMENTS: Any mammogram. Predictors included race, number of visits to a primary care physician (0, 1, 2, or 3 or more), median income of ZIP code of residence (a surrogate measure of income), and state.
RESULTS: The following are findings from Georgia; similar results were found in each state studied. The mean age of the 335,680 women was 75 years; 20% were black. Sixty-eight percent of the black women and 69% of the white women made at least one visit to a primary care physician. Overall, 14% of the women had had mammography; black women had mammography less often than white women (9% compared with 15%). At each primary care visit level (1, 2, or 3 or more visits), black women had mammography less often than white women (1 visit, 7% compared with 15%; 2 visits, 12% compared with 21%; and 3 or more visits, 12% compared with 20%). Even among women who had made at least one visit to a primary care physician, a deficit for blacks occurred in each income quintile (lowest quintile, 13% compared with 20%; low, 10% compared with 18%; middle, 12% compared with 18%; high, 10% compared with 19%; and highest, 12% compared with 22%) and in each state (in Georgia, for example, the percentages were 14% compared with 21%). An age-, income-, and state-adjusted logistic model predicting mammography use for 2.9 million white women in all 10 states shows the powerful effect of primary care use on mammography (odds ratios for 1, 2, and 3 or more visits were, respectively, 2.73 [95% CI, 2.70 to 2.77]; 3.98 [CI, 3.93 to 4.03]; and 4.62 [CI, 4.58 to 4.67]). The same model fit to 250 000 black women shows a lesser effect (analogous odds ratios were 1.77 [CI, 1.67 to 1.87]; 2.49 [CI, 2.36 to 2.63]; and 3.15 [CI, 3.04 to 3.25]).
CONCLUSION: Among older women, mammography is used less often for blacks than for whites. More frequent use of mammography is associated with more visits to a primary care physician in both groups, but the deficit for black women persists at each income level and in each state, even after primary care use is considered. Primary care visits are less likely to "boost" mammography use for black women than for white women.