Breast Cancer Screening Among Adult Women — Behavioral Risk Factor Surveillance System, United States, 2010

Jacqueline W. Miller, MD

Jessica B. King, MPH

Djenaba A. Joseph, MD

Lisa C. Richardson, MD

Division of Cancer Prevention and Control, National Center for Chronic Disease Prevention and Health Promotion

Corresponding author: Jacqueline W. Miller, MD, National Center for Chronic Disease Prevention and Health Promotion, CDC, 2858 Woodcock Boulevard, MS K-57, Atlanta, GA 30341. Telephone: 770-488-5061; Fax: 770-488-3230; E-mail: aci8@cdc.gov.

Introduction

Breast cancer continues to have a substantial impact on the health of women in the United States. It is the most commonly diagnosed cancer (excluding skin cancers) among women, with more than 210,000 new cases diagnosed in 2008 (the most recent year for which data are available) (1). Incidence rates are highest among white women at 122.6 per 100,000, followed by blacks at 118 per 100,000, Hispanics at 92.8, Asian/Pacific Islanders at 87.9, and American Indian/Alaskan Natives at 65.6 (1). Although deaths from breast cancer have been declining in recent years (2,3), it has remained the second leading cause of cancer deaths for women since the late 1980s with >40,000 deaths reported in 2008 (1). Although white women are more likely to receive a diagnosis of breast cancer, black women are more likely to die from breast cancer than women of any other racial/ethnic group (1). In addition, studies have demonstrated that nonwhite minority women tend to have a more advanced stage of disease at the time of diagnosis (4,5). Breast cancer also occurs more often among women aged ≥50 years, those with first-degree family members with breast cancer, and those who have certain genetic mutations (4,5). Understanding who is at risk for breast cancer helps inform guidelines for who should get screened for breast cancer.

In 2002, the U.S. Preventive Services Task Force (USPSTF) recommended screening mammography, with or without a clinical breast exam, every 1–2 years for women aged ≥40 years (6). Mammography has been demonstrated to reduce breast cancer mortality by detecting breast cancer early, when treatment is most effective (7,8). Mammography use increased in the 1990s, when it became a widely accepted practice for decreasing breast cancer mortality, but its use decreased during 2000–2005 (9,10). Studies that assessed this decline noted that women with insurance and higher annual incomes had the highest decrease in mammography use. In a follow up study, the overall prevalence of receiving mammography within the past 2 years rose slightly in 2006 to approximately the 2000 level (11). The latest report using 2008 data indicated that mammography use among women aged 50–74 years has essentially leveled off since 2000 (12). During 2000– 2006, although non-Hispanic white women and those with insurance had a substantial overall decline in mammography use, women who were uninsured, those who had lower annual income or education levels, and members of certain minority racial/ethnic groups persistently reported lower prevalence of mammography use (11,12). Moreover, substantial geographic variation in screening rates exists across the United States (13).

In November 2009, USPSTF changed its breast cancer screening recommendations to biennial mammography for women aged 50–74 years and stated that women aged 40–49 years do not need to be screened routinely (6). However, the Patient Protection and Affordable Care Act of 2010 (as amended by the Healthcare and Education Reconciliation Act of 2010 and referred to collectively as the Affordable Care Act [ACA]) specifically designates coverage of the breast cancer screening according to the recommendations issued before November 2009 (ACA §2713) (14).

This report summarizes the 2010 national mammography use prevalence estimates for women aged ≥40 years, by demographic characteristics and state-level prevalence estimates, based on the 2002 USPSTF recommendations. This information can be used by providers, public health practitioners, and other stakeholders as baseline data for assessing progress and gaps in breast cancer screening as the Affordable Care Act is implemented.

Methods

To estimate the prevalence of breast cancer screening using mammography among women aged ≥40 years in the United States, CDC analyzed 2010 data from the Behavioral Risk Factor Surveillance System (BRFSS). BRFSS is an ongoing, state-based, random-digit–dialed telephone survey of the civilian, noninstitutionalized adult population aged ≥18 years. The survey gathers information on health behaviors, chronic diseases, and preventive health practices from all 50 states, the District of Columbia (DC), Guam, Puerto Rico, and the U.S. Virgin Islands. In every even year, the survey contains a women's health module that includes two questions related to mammography use. Participants are asked whether they have ever had a mammogram, and those who respond affirmatively are asked how long it has been since their last mammogram. Missing, refused, and "don't know" responses were excluded from analyses. In 2010, among the 276,995 female survey participants, 228,871 were aged ≥40 years and were asked the questions regarding mammography use, accounting for a total sample of 221,241 participants included in this analysis.

All data were weighted to the respondents' probability of selection, and sex, age, and race/ethnicity for each state's population using intercensal estimates. Percentages were age-adjusted to the BRFSS female population aged ≥40 years. Percentages and 95% confidence intervals were calculated using SAS (SAS Institute Inc., Cary, North Carolina) and SUDAAN (Research Triangle Institute, Research Triangle Park, North Carolina) software. The median response rate for the Council of American Survey and Research Organizations (CASRO) was 54.6% (range: 39.1%–68.8%) and the CASRO cooperation rate was 76.9% (range: 56.8%–86.1%).* Current use of mammography was defined as having a mammogram within the past 2 years.

Results

In 2010, an estimated 75.4% women aged ≥40 years and 79.7% of women aged 50–74 years reported having a mammogram within the past 2 years (Table 1). Women who reported the highest prevalence of mammography use were those aged 60–69 years (81.3%) and 70–74 years (82.4%), non-Hispanic blacks (78.6%), those with college graduate or higher level of education (80.8%), those whose annual household income was ≥$75,000 (83.8%), those with health insurance (78.6%), and those with a usual source of health care (78.3%). Women who reported the lowest prevalence of mammography use were those aged 40–49 years (68.8%), American Indian/Alaska Natives (63.9%), those who did not graduate from high school (65.9%), those whose annual household income was ≤$15,000 (63.2%), those with no health insurance (50.4%), and those with no usual source of health care (43.6%).

The age-adjusted prevalence of reported mammography use within the study period (i.e., past 2 years from the time of the 2010 BRFSS interview) varied among the states, ranging from 63.7% in Idaho to 84.2% in Massachusetts (Table 2). Although mammography use prevalence varies considerably across the United States, the majority of states with the highest prevalence are located in the northeast region. Many states with the lowest prevalence estimates have more rural, less populated areas.

Discussion

In 2010, approximately 25% of women aged ≥40 years were not current with their mammography use according to the 2002 USPSTF guidelines. Mammography use was lower among American Indian/Alaska Native women, women with lower levels of education and annual household income, and women with no health insurance or usual source of health care. The geographic variation noted in mammography use ranged from 63.7% to 84.2%. Mammography use has not substantially changed since 2000 (76.5% [95% confidence interval (CI): 75.9–77.0]), consistent with previous reports examining 2006 (11) and 2008 (12) data. The geographic variation noted in these findings is similar to that noted in the 2000 and 2006 data (13). Multiple factors account for this variation, including the availability of large university hospital systems, geographic density of healthcare providers, level of insurance coverage in the population, accessibility to mammography facilities, and levels of annual income. The finding that women without health insurance or a usual source of health care have lower mammography use supports previous reports that a physician's recommendation for mammography is the most important influence for a woman to obtain a mammogram (15). Persistent lower mammography use among certain minority populations will continue to result in patients receiving a diagnosis of breast cancer at later stages and a potentially slower decrease in breast cancer death rates. One study addressing preventable deaths in the United States has estimated that a 5% increase in mammography use could prevent 560 deaths from breast cancer each year (16). Therefore, increasing mammography use among women, especially those with low use prevalence, might decrease breast cancer mortality substantially . More research is needed to help understand why these disparities exist and provide appropriate interventions that reduce or eliminate them.

To help address disparities in mammography use, CDC administers the National Breast and Cervical Cancer Early Detection Program (NBCCEDP) (17). NBCCEDP provides free or low-cost screening and diagnostic breast and cervical cancer services to low-income, under- and uninsured women and provides access to state Medicaid programs for treatment if breast or cervical cancer are diagnosed. NBCCEDP has reduced mortality among the medically uninsured (18) and prevented 0.6 deaths for every 1,000 women screened (19).

As a result of provisions in the Affordable Care Act, Medicare now covers adult clinical preventive services graded A (strongly recommended) or B (recommended) by the USPSTF and immunizations recommended by the Advisory Committee on Immunization Practices with no cost sharing to beneficiaries (ACA §2713). Starting in 2014, these services, along with recommended preventive services for children, youth, and women, will be covered at no cost sharing by newly qualified private health plans operating in the state-based insurance exchanges.† Beginning in 2013, state Medicaid programs that eliminate cost sharing for these clinical preventive services may receive enhanced federal matching funds for them (ACA §4106).

The Affordable Care Act focuses on reducing health disparities by removing barriers to preventive health screening such as reducing out-of-pocket costs and expanding access to care by increasing availability of health-care providers and services through provisions such as the essential health benefits package (ACA §1302), state health-care workforce development grants (ACA §5102), and public health workforce recruitment and retention programs (ACA §5204). Implementation of the Affordable Care Act is expected to result in an increase in mammography use among many more women of appropriate screening age and in a decrease in disparities among underserved populations by vastly expanding insurance coverage among the uninsured population. Using evidence-based interventions to increase breast cancer screening by addressing other barriers to screening, as recommended by the Guide to Community Preventive Services, might further decrease breast cancer mortality nationwide (20,21). These evidence-based interventions target both clients and providers. Client-oriented interventions (e.g., client reminders, small media, group education, one-on-one education, reducing structural barriers, and reducing out-of-pocket costs) are directed toward educating clients and removing barriers that interfere with screening (20). Provider-oriented interventions (e.g., recall and reminder systems or assessment and feedback systems) are designed to increase knowledge and develop system-level approaches to increase provider recommendation and delivery of cancer screening services (21).

The findings provided in this report are subject to at least three limitations. First, the data are self-reported and not validated from medical or billing records. Studies have demonstrated that women often over-report having a recent mammogram. For example, a recent report indicated that black women tend to over-report twice as often as white women (22). Adjusting for this over-reporting resulted in a considerable decrease in reported mammography use of 29 percentage points among black women compared with 12 percentage points among white women (22). Second, because the BRFSS survey questionnaire does not ask why a woman had a mammogram, whether the mammogram was for screening or diagnostic purposes can not be determined. Finally, because BRFSS samples civilian, noninstitutionalized persons by telephone, and only those with landlines are represented in this sample, these data might not be nationally representative.

Conclusion

Reducing personal costs and expanding insurance coverage are important factors that will help to ensure that more women receive mammography screening (20). Developing new and effective interventions to increase mammography use relies upon better understanding of who is not receiving recommended breast cancer screening and the reasons for lack of screening. Although clear communication for individualized decision-making is difficult, helping women to understand their personal risk (e.g., family history of breast cancer, menstrual history, use of estrogen, and genetic abnormalities) is also important for changing a woman's behavior and acceptance of the need to undergo screening (23–25).

Public health efforts to monitor the use of clinical preventive services such as mammography screening will be necessary as the Affordable Care Act is fully implemented over the next few years. Understanding the interaction between individual, community-level, and federal-level activities will help identify promising practices and unsuccessful efforts that require modification. In particular, close monitoring of mammography screening will help to identify potential concerns regarding low use of this early detection test, which could lead to negative outcomes such as an increase in late stage breast cancer diagnoses and breast cancer mortality. The ACA includes the Prevention and Pubic Health Fund (ACA §4002) to increase the use of clinical preventive services at the community level. The establishment of additional interventions such as cancer screening registries to monitor outcomes of abnormal screening results, patient navigation services (i.e., assistance to help patients facilitate access to services and overcome barriers), and electronic health records could help ensure the U.S. population gets all the appropriate clinical preventive services.

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