5-year mammography rate
Efforts to increase screening through national media campaigns and Medicare financial coverage have increased mammography rates over time, but to our knowledge have had little impact on many older women. In the 5 years from 1993 to 1997, 43% of women age ≥ 65 years in 1993 had never undergone a mammogram and an additional 16% had undergone only 1 mammogram. Therefore, nearly 60% of older women were not taking advantage of the Medicare benefit for mammography every 2 years. It is unlikely that the expansion of the Medicare benefit in 1999 to cover a mammogram every year will change mammography use by the majority of older women.
Predictors of mammography
The number of physicians involved in care (i.e., billing for services) is the single strongest predictor, both in “raw” association and even more strongly as an independent predictor when measures related to health (e.g., number of inpatient admissions) are held constant. A likely mechanism is that in being exposed to more physicians, a woman is more likely to encounter a physician who recommends having a mammogram and having mammograms on a routine basis.
When other predictors are controlled, the number of inpatient admissions appears to have a strong independent negative relation with ever having undergone a mammogram and with having repeated mammograms. Patients with more inpatient admissions are likely to be in poor health. Physician encounters would likely focus on acute illness rather than preventive care.
Increasing age appears to have a relatively strong independent negative relation with ever having undergone a mammogram and a lower, but meaningful negative independent relation with having repeated mammograms. Many previous studies have found a negative relation between age and mammography for older women.7, 13, 14 This relation most likely reflects perceptions of both older women and their physicians that as people age, preventive health care is less important-that increasing age, independent of health status, is a reason not to be screened. The effect of age independent of health status has been reported by others.15
The type of physician seen appears initially to be strong predictor. When other characteristics of women are controlled, the independent relation between the type of physician seen and ever having undergone a mammogram is lower but still meaningful. The rate for ever having undergone a mammogram was 71% for women who saw an Ob/Gyn and approximately 55% for women who did not see an Ob/Gyn (Table 3). Ob/Gyns may be more likely than other physicians to recommend a mammogram. Older women who continue to see Ob/Gyns may be more interested in preventive care, such as mammography. Whatever the process, it applies only to getting one mammogram, having repeated mammograms does not appear to differ by type of physician seen.
Other than age, demographic characteristics did not appear to have any meaningful independent association with mammography utilization in this population and time period. Race and urban or rural location were found to have little effect. Education, income, and being below poverty level also were found to have little effect, at least when they were represented by the zip code in which the individual lived. The lack of relation between these measures most likely reflects the success of previous efforts to address demographic disparities in mammography use. Making mammography a covered Medicare benefit reduced the importance of income as a barrier to obtaining a mammogram. Major information campaigns have reduced the importance of education level. To the extent that racial differences were the result of underlying differences in income and education, efforts addressing those issues addressed racial differences as well. In Michigan, access was addressed by locating mammography facilities in every county so that women in both urban and rural locations have access to mammography services.