Incidence rates of in situ
and invasive breast cancer among women aged ≥50 years in the United States have dropped since 1999.2
Despite a decline in the incidence of breast cancer in the last decade, breast cancer remains one of the leading causes of mortality and morbidity among women in the United States.53
Reduction in breast cancer incidence is mainly attributed to the reduced use of hormone replacement therapy (HRT) after publication of the results of the Women's Health Initiative (WHI) Estrogen Plus Progestin trial in 2002.54,55
However, the decline in breast cancer incidence may also be due to a decrease in mammography screening in the United States.53
Results of this study show an overall decline in the annual and biennial screening rates over a 10-year period (1999–2008) among women recipients aged 40–64 years in the WV Medicaid FFS program. Screening rates for women aged ≥40 years significantly increased nationally from 1987 to 2000 before showing a declining trend in the following decade.5,23,24
Our findings show similar trends of increase in screening use between 1999 and 2000, followed by a steady decline in the Medicaid FFS population aged 40–64 years.
Among women recipients in the WV Medicaid FFS program, the screening rates dropped consistently across all age, race, and location of residence categories, although the annual screening rates among women aged 60–64 years showed an increasing trend. The annual screening rate in women aged 60–64 years increased slightly from 27.0 in 1999 to 28.2 in 2008. Annual and biennial screening rates were higher in women aged 50–59 years compared to women in other age groups. These results are consistent with findings based on NHIS data, where screening rates were found to be higher in women >50 years compared to women aged 40–49 years.24
Results of this study also indicate declining annual and biennial screening rates during 2000–2008 among women 40–49 years of age compared to women in the older age groups. These results are consistent with other reports suggesting an overall decline in the screening rates between 2000 and 2006 among American women aged 40–49 with healthcare insurance coverage.56
Annual and biennial screening rates among women recipients in the WV Medicaid FFS program were lower than the screening rates for the overall female population in West Virginia and the United States during the 10-year period (1999–2008). Our results are consistent with previous studies, which also had demonstrated lower screening rates among women recipients enrolled in Medicaid programs.50,57
Studies consistently have found lower screening rates among women with public health insurance, including those with Medicaid coverage, compared to those with private health insurance.23,24,34,40
Annual and biennial screening rates were higher among white women compared to their counterparts from other racial groups (including African Americans). A study involving church-based intervention to improve mammography reported that white women had higher biennial screening rates compared to their Latina counterparts, during both baseline and follow-up periods.57
These finding are in contrast with the results of another study examining breast cancer screening in North Carolina Medicaid recipients aged ≥50, in which white women were less likely to have been screened than African American women.50
In this study, screening rates among women residing in nonmetro-rural areas were higher compared to women residing in metro-urban and nonmetro-urban areas. This result is in contrast to previous studies that have found lower screening rates among women residing in rural areas compared to those in urban areas.23,38
Rural areas are often characterized by longer distances between facilities providing medical care, women without insurance, lower household income, and lower education attainment compared to urban regions.38,58
Therefore, women residing in rural areas are more likely to underuse screening compared to women residing in urban areas. There are reports suggesting improvement in screening use among uninsured, low-income women over the last decade, however, although this improvement is small in magnitude and lower than the target screening rate.48
The reported improvement in screening use may be attributed in part to the promotion programs targeted to increase screening among underserved populations, such as the NBCCSP, a nationwide comprehensive public health initiative funded by CDC. Alternatively, West Virginia being a predominantly rural state, higher screening rates and the absolute change in screening rates from 1999 to 2008 in women residing in nonmetro-rural areas compared to those living in metro-urban and nonmetro-urban areas in West Virginia may be purely coincidental.
The efficacy of screening in early detection of cancer and subsequent reduction in the mortality rate primarily depends on adherence to screening recommendations.59
Studies have reported increased screening rates in the last decade for the overall female population in the United States, yet screening adherence among women followed over time was found to be low.22,60,61
Overall persistence with screening was very low in our study, with only 8.6% of Medicaid FFS women having 8–10 screening over the 10-year period (1999–2008).
Despite widespread breast cancer awareness and screening initiatives by various health organizations, overall screening rates and persistence with screening in women aged 40–64 in the WV Medicaid FFS program was far below the Healthy People 2010
goal of biennial screening rate of 70% and also below the state and national overall screening rates for women. In this study, screening persistence significantly differed across different age and location of residence categories. Higher screening persistence was observed in women aged ≥50 than in women in their 40s (11.2%vs.7.4%). Prior studies have reported a screening persistence of 46.1% in women aged ≥50, whereas 44.6% women aged 43–49 were persistent with screening.42,62
Persistence with screening was higher among women residing in the nonmetro-rural area.
The findings of this study are subject to several limitations. Medicaid claims data are collected mainly for reimbursement purposes, and, therefore, it is difficult to determine the completeness and accuracy of the data. Coding errors are likely to occur during processing of the claims. Claims data have been reported to underestimate the use of preventive procedures.63
Mammography screening done as a part of community-based cancer screening and prevention services where Medicaid was not billed are difficult to account for and could cause underestimation of screening rates. It is possible that some screening mammograms may have been coded as diagnostic mammograms during the process of creating a claim for such visits. The WV Medicaid data were used as provided to us, and no testing was done for potential level of accuracy of claims associated with coding error.
Women with a past diagnosis of breast cancer, other breast abnormalities, mastectomy, lumpectomy, and other breast-related procedures were excluded from the study. Identification of women with a diagnosis of breast cancer and breast abnormalities using only ICD-9 codes can cause underestimation of breast cancer cases because of a lack of specific clinical definitions under ICD-9 CM. However, a medical history of such diagnoses or surgical procedures among women recipients in the WV Medicaid FFS program before the study period was not possible to determine because data before 1999 were unavailable. WV Medicaid data were not linked with cancer registry data; such a linkage may have identified women diagnosed with breast cancer who were missed because of the use of Medicaid claims data alone. Encounter data for recipients enrolled in WV Medicaid managed care programs were also not available and are not included. Dual enrollees (those <65 years old but eligible for Medicare and Medicaid) were included, but because Medicare would be their primary payer for mammography screening, these encounters may not have been captured in our analysis. Mammography screening rates by Medicaid eligibility groups were not reported because there was no grouping variable in the data. Reporting eligibility status by year for the Medicaid program as a whole is possible, but it may not necessarily reflect the proportion of individuals by eligibility category in the FFS program. Our results should be interpreted in light of these limitations.
This study is of particular importance for the state of West Virginia as well as the Appalachian region, which is characterized by its largely poor, undereducated, medically underserved, and geographically dispersed rural population with significant health disparities. West Virginia is the only state situated entirely in the Appalachian region. Breast cancer is one of the most prevalent cancers among women in West Virginia, with reported disparities in screening and mortality.64
This study highlights the lower breast cancer screening rates among women recipients in the WV Medicaid FFS program regardless of which screening guidelines are considered. Persistence with mammography screening was also found to be low among women recipients in the WV Medicaid FFS program.
Many previous studies have found lower mammography rates among women with low socioeconomic status (SES).40,45–48
Although all people who qualify to receive health coverage under the Medicaid program have lower SES based on the federal poverty level, the financial barriers preventing access to screening services are removed for these women because of healthcare insurance coverage provided by Medicaid. The lower screening rates found in this study clearly indicate that factors other than lack of insurance coverage, such as poor knowledge about screening benefits, negative attitudes toward preventive practices, cultural beliefs, nonavailability of screening facilities, lack of physician's recommendations, lack of transportation, and child care issues, may influence screening practices among low-income women recipients in the Medicaid FFS programs.
Medicaid FFS recipients are traditionally known to be sicker or more disabled than their managed care counterparts and are present in all state Medicaid programs. Thus, even though this study focuses on the WV Medicaid FFS population, the mammography screening differences and trends noted in this vulnerable population segment are likely to be true in Medicaid beneficiaries enrolled in the FFS programs in other states as well and may have similar policy implications. Further research is needed to determine factors associated with lower screening and persistence rates among these women.