According to unadjusted and age-adjusted BRFSS data, there was little to no disparity from 1995 through 2006 between the percentages of black and white women aged 40 years or older who had a mammogram during the past 2 years. Also, mammography use rates for both black and white women were consistently at or above the Healthy People 2010 objective of 70%. However, after adjustment for respondent misclassification, mammography use rates for neither white women nor black women had attained the Healthy People 2010 objective by 2006, and a disparity between white and black women emerged.
Lack of a disparity in mammography use between black and white women has been widely reported among studies that focus on racial, ethnic, and socioeconomic disparities (2
). However, the results presented in our study suggest that previous notions of black-white parity in mammography use should be reexamined (13
). Women of lower SES, immigrant women, black women, and women from other minority racial or ethnic groups remain populations of concern because of disparities in stage of breast cancer at diagnosis and breast cancer death rates (16
). The disparity in mammography use observed in our study may help explain racial disparities in stage of breast cancer at diagnosis and in breast cancer death rates. Other factors that might contribute to the incidence-mortality paradox include differences in the biology of the disease between black women and white women, differences in stage at diagnosis that are unassociated with mammography use, and differences in treatment following diagnosis (11
Lack of access to care — because of high cost, not having a usual source of care, or lack of health insurance — remains a barrier to mammography use. Lower-income, elderly, and immigrant women may encounter barriers because of language or health literacy problems. Additional factors that may reduce mammography use and contribute to disparities include patient knowledge, attitudes, and cultural beliefs (22
). For example, Rawl and colleagues found that white women perceived greater benefits from receiving a mammogram than did black women (23
This study has several limitations. Ideally, the measures of validity used to adjust BRFSS prevalence estimates would be based on studies of nationally representative samples of women. Although such data are not available, the studies included in the meta-analysis by Rauscher et al (4
) do include white and black women from a spectrum of ages (40 years or older), regions, and SES groups. Rauscher et al do not report a significant difference between the specificity of self-reported mammography use data for black and white women (0.49 vs 0.62); however, the 95% confidence intervals for these measures do not overlap (0.42-0.57 vs 0.61-0.64). The number of studies that measured sensitivity and specificity for black women was limited; thus the values obtained by Rauscher et al may be vulnerable to sample variation, external generalizability, and other sources of measurement error. Also, the application of measures of validity from the random-effects meta-analysis does assume study-to-study variability and suggests uncertainty in estimating the underlying parameters (ie, sensitivity and specificity) (4
Additional limitations are that the sensitivity and specificity measures that we used did not account for SES. Although sensitivity and specificity may differ between women with higher and lower SES, there is a dearth of literature in this area (4
). The sensitivity and specificity measures also did not account for other factors such as attitudes and women's knowledge of breast cancer and screening mammography. Another limitation is that the BRFSS questionnaire (similar to other comparable national surveys) does not distinguish whether a woman received a mammogram for screening or diagnostic purposes. Finally, the median state and territorial Council of American Survey Research Organizations response rates for BRFSS have been low in recent years; from 2000 through 2006 they ranged from 49% to 58%. Median cooperation rates during the same period ranged from 53% to 77% (26
Most studies that have measured the validity of mammography survey questions were conducted in the 1990s. These studies should be repeated to confirm whether sensitivity and specificity have changed. Such studies should be conducted in diverse populations and include an assessment of data sources such as medical and billing records.
In addition to updating validity measures of the standard wording in surveys of mammography use, it would also be useful to identify alternative wording that might have higher validity. Most surveys, including BRFSS and the National Health Information Survey, use the following introductory wording: "These next questions are about mammograms, which are X-ray tests of the breast to look for cancer." In 1992, BRFSS used different introductory wording: "I would like to ask you a few questions about a medical exam called a mammogram. A mammogram is an X-ray of the breast and involves pressing the breast between two plastic plates."
The reported prevalence of mammogram use was lower when this more graphic wording was used than when standard wording was used; this reduction in prevalence was greater among black women than white women (27
). These effects on measured prevalence are consistent with the hypothesis that questionnaire language that clarifies that a mammogram involves "pressing the breast between two plastic plates" improves the specificity (ie, results in fewer false-positive responses).
Cultural sensitivity and awareness should be applied when addressing black-white and other racial/ethnic disparities in breast cancer detection and treatment. To be effective, interventions designed to overcome persistent inequalities must take into account differences in race, culture, language, SES, and age (24
). Our study reinforces that these considerations can apply to the validity of surveillance data as well (4
). Surveillance, intervention, and policy must account for the unique characteristics of women from each racial/ethnic group. Increasing mammography use — especially among underserved populations — remains a priority as public health professionals strive to eliminate breast cancer disparities and to decrease breast cancer death rates.