The Centers for Disease Control and Prevention (CDC) provides low-income, uninsured, and underserved women access to timely, high-quality screening and diagnostic services to detect breast and cervical cancer at the earliest stages through the National Breast and Cervical Cancer Early Detection Program (NBCCEDP) (1). In 1993, Congress authorized CDC to develop a combined approach to women's health by offering heart disease and stroke prevention services to women enrolled in the NBCCEDP.

The heart disease and stroke prevention program, later named the Well-Integrated Screening and Evaluation for Women Across the Nation (WISEWOMAN) program, was first funded in 1995 (2). Low-income women aged 40 to 64 years enrolled in the NBCCEDP are qualified for WISEWOMAN.

Many health interventions include testing for cholesterol, blood glucose, and blood pressure, but WISEWOMAN also provides lifestyle intervention and referral services. Through WISEWOMAN, qualified women receive chronic disease risk factor screening and health education interventions that help them lower their risk for heart disease. By helping women adopt healthy eating patterns and encouraging them to be more physically active, WISEWOMAN aims to help women know their risk for heart disease and develop a heart-healthy lifestyle.

The coordination of these two programs is one example of an integrated and comprehensive approach to improving the public's health. The successful implementation of such an approach, however, requires comprehensive changes to health care systems (3). Understanding how the coordination of multiple chronic disease programs might enhance the effectiveness of each is key to advancing prevention efforts. As part of an overall assessment on the benefits of combined approaches to preventive health, WISEWOMAN and the NBCCEDP are conducting analyses to explore these relationships. This report describes the results of one part of those analyses: a comparison of breast cancer rescreening rates among NBCCEDP participants who also participated in the WISEWOMAN program with rescreening rates among NBCCEDP participants who did not.

Across all 10 programs, participation in both WISEWOMAN and the NBCCEDP was associated with a higher percentage of follow-up mammograms, with adjusted odds ratios ranging from 1.5 to 5.1 (Table 1). Overall, women who participated in both the NBCCEDP and the WISEWOMAN program were 2.8 times more likely to have received a follow-up mammogram than were women who participated in the NBCCEDP alone (Table 2). The demographic characteristics associated with an adjusted greater likelihood of having had a repeat mammogram were being aged 50 or older and being white (Table 2).

Among the 13,742 women who participated in both programs, certain characteristics increased the likelihood that women received a follow-up mammography screening. Rescreening rates were significantly higher among those older than 49 years. American Indian or Alaska Native women and women of unknown races had higher rates than did whites, blacks, Hispanics, and Asians. Nonsmokers were more likely to be rescreened than were smokers. Those who received follow-up WISEWOMAN screening services within a year of their initial WISEWOMAN screening were more likely than those who did not to receive a mammography rescreening  (Table 3). Adjusted results indicate that WISEWOMAN participants who received a follow-up WISEWOMAN screening within a year of their initial WISEWOMAN screening were 5 times more likely to return for a follow-up NBCCEDP mammogram than were WISEWOMAN participants who did not.

Excluding nonmelanoma skin cancer, breast cancer is the most common form of cancer among U.S. women, and it accounts for a third of newly diagnosed cancer cases among women each year (6). Although appropriate preventive services, including mammography screening, have been shown to reduce the number of cancer deaths (7), mammography screening is underused (7,8). Estimates of the percentage of women who have undergone mammography screening range from 32% to 91%, while estimates of the percentage that have undergone rescreening range from 28% to 92% (4,9). However, estimated screening rates are substantially lower among financially disadvantaged populations, such as those served by the NBCCEDP and WISEWOMAN (4,5). In an NBCCEDP study of rescreening rates at selected sites (which reflected rescreenings that program participants reported receiving outside the NBCCEDP as well as program-delivered rescreenings), average rates were as high as 72.4% after 18 months and 81.5% after 30 months; however, rescreening rates were lower in the most disadvantaged populations — women who were older, were of racial/ethnic minorities, and had lower levels of education (9).

Although the rescreening rates among women in this cohort who were older, white, American Indian or Alaska Native, or WISEWOMAN participants are encouraging, the overall results show that practices and strategies to increase rescreening rates among underserved women need to be developed. The chances that a patient will follow cancer screening recommendations are influenced both by personal factors and by the patient's health care environment. Thus, understanding the interplay of these factors is critical for the development of effective cancer prevention programs (3).

Joint participation in the NBCCEDP and the WISEWOMAN programs may be associated with higher cancer rescreening rates for at least three reasons. First, women in the NBCCEDP who choose to participate also in WISEWOMAN are likely to be more committed to their overall health care than those who choose not to participate (3). Second, women participating in both WISEWOMAN and the NBCCEDP may feel that they are receiving better, more comprehensive health care service and thus be more likely to return for follow-up screening as recommended (3,10). Finally, in addition to receiving annual reminders from the NBCCEDP about the importance of regular screenings for breast and cervical cancer, women who also participate in WISEWOMAN receive comprehensive cardiovascular disease screening and a series of culturally sensitive lifestyle interventions that provide additional contact with health care providers (10). In effect, WISEWOMAN reminder practices and multicomponent interventions may serve to reinforce the rescreening reminders that NBCCEDP participants receive, resulting in at least a doubling of the number of times that participants are prompted to be rescreened, a factor that might be critical for financially disadvantaged populations.

Findings from other studies also indicate that coordinated health care efforts have a synergistic effect. For example, in a meta-analysis, researchers found that interventions designed to increase older women's access to health care were more effective when used in conjunction with promotional strategies directed at individuals than access-enhancing strategies alone (11).

The findings in this report are subject to several limitations. The sample sizes for the variables listed in the tables differ because of missing data; however, missing data should have had little effect on the estimates presented here, given that the demographic profile of participants with missing data was not significantly different from that of participants with complete data. Mammography screening guidelines recommend annual or biennial screening for women aged 40 or older, whereas the rescreening rates reported here are based on a follow-up period of 18 months. Another limitation is that this study did not capture rescreening that NBCCEDP participants may have undergone outside of the NBCCEDP, nor did it adjust for differences in participants' mammography screening history or for the timeliness of historical screenings; these are all characteristics that might indicate other sources of funding for mammograms, as well as secular trends. Finally, women who are highly health-conscious may be more likely to participate in both WISEWOMAN and NBCCEDP and may be more likely to return for NBCCEDP rescreening.

Overcoming this self-selection bias in future NBCCEDP/WISEWOMAN studies will be difficult because, if the programs are fully integrated, women will have no choice but to attend both, effectively ensuring that motivation is not the key factor in attending. Thus, researchers will be unable to compare rescreening rates of women who attend both programs with the rates of those who attend only one program. Measuring health motivation and ensuring that all study participants are equally motivated might be another way to address this issue of self-selection bias. However, neither program currently has a measure of health motivation. Thus, the data provided in this study are the strongest available for these two programs.  

The results of this analysis suggest that participation in both the NBCCEDP and WISEWOMAN may result in better adherence to mammography rescreening recommendations. A number of likely explanations for these results have been proposed: women who receive multiple services may be more invested in the program or, alternatively, women who are more health-conscious may be likely to select a more intensive combined program. Consequently, further research is needed to better understand the reasons behind these findings.