This report extends previous research on mammography through examination of socio-demographic characteristics, theoretically informed attitudinal variables, and barrier types associated with annual-interval mammography use for women in their 40s. Few studies have focused on women in their 40s; far fewer have examined annual-interval mammography for this population.
Overall, 44.8% of women in this sample were adherent to annual-interval mammography – slightly lower than other studies of reported rates of repeat mammography [3
]. Our lower rate may be attributed to several factors. Most prior studies used longer screening intervals to define repeat use (e.g., every two years), compared with our use of an approximately annual interval (10 to 14 months). Widening the length of time between repeat screenings increases the proportion of women categorized as screened and, thus, classified as adherent [4
]. In addition, many previous studies assessed repeat use only for women aged 50 and over. Our lower-than-expected rate of repeat screening may also have resulted from the precision with which we measured repeat use. We assessed specific intervals between past two mammograms through claims data confirmed via telephone interviews. In contrast, methods in prior research, such as averaging the number of self-reported mammograms over a number of years, may inflate proportions categorized as adherent. Accurate assessment of repeat mammography use is a growing concern for applied researchers as study findings have been shown to differ according to how this outcome is operationalized [4
Demographic variables previously associated with repeat mammography, such as race, marital status, education and income [4
] were not significant in our study. This could be a consequence of eligibility criteria. At baseline, all participants were insured with the State Health Plan and had recent mammograms prior to study enrollment, resulting in a sample that may be more homogeneous than some other studies.
We found several medical and healthcare-related factors associated with mammography use. About 40% of our sample reported histories of abnormal mammograms, consistent with other reports of cumulative assessment. Elmore and colleagues estimated the risk of an abnormal mammogram was 49% across 10 screening mammograms [48
]. Having a history of abnormal mammograms was associated with screening here and in other research [38
]. Women with histories of abnormal mammograms may have higher distress and anxiety about breast cancer [50
], which may explain better adherence to routine screening. Also, they are more likely to be advised by their physicians to be screened [51
]. Also consistent with prior research, we found that family history of breast cancer increased the likelihood that women would be adherent to mammography [52
]. The benefits of annual-interval screening may be more salient for women who have had family members with breast cancer [55
]. Of our healthcare-related variables, only reminders were associated significantly with the outcome. Women who said they had not received mammography reminders were less likely to be adherent to mammography. This is consistent with previous studies demonstrating the efficacy of reminders to increase mammography use [20
Finally, women with more self-reported barriers to mammography were less likely to obtain annual-interval mammograms [17
]. Our analyses support and extend these results in that some barriers may be more influential than others. Being too busy and forgetting to make or keep mammography appointments were commonly reported and associated with annual-interval use. These barriers have been among the most commonly-mentioned barriers since they were first assessed [60
]. They underscore the importance of reminders in promoting regular screening. Reporting being too busy and forgetting to make or keep mammography appointments may reflect competing priorities in women's lives. Given the demands of work, family and other activities, early detection health services, such as mammography, may compete with other priorities for women in their 40s. Although some mammography facilities attempt to accommodate busy women by providing extended weekday hours and/or Saturday appointments, these practices are uncommon [62
]. Health professionals should emphasize making regular mammograms a priority and work with women to identify how they can build mammograms into their lives [63
Our finding that cost was a commonly-reported and influential factor is consistent with previous literature [28
]. At the time of data collection, mammography screening was covered by the State Health Plan every two years for women in their 40s in contrast to every year coverage for women aged 50 and older. Annual coverage was since extended to women in their 40s. In the future, we will assess whether this policy change decreases women's reports of cost as a burden. It is not clear when women identify cost as a barrier whether they understand what their out-of-pocket expenditures would be and whether they are considering other costs as well (e.g., childcare, time lost from work, travel-related expenses).
Barriers associated with lack of knowledge about mammography or not thinking mammograms are needed were frequently cited in our sample and associated with non-adherence. This may be a result of well-publicized controversy over the interval and effectiveness of screening for women in their 40s [8
]. Health professionals may need to take extra care in discussing the risks and benefits of mammography screening for women in their 40s, as ambiguity about the need for regular mammograms may be an issue for this group.
Our study has some limitations. First, these are cross-sectional data which preclude determination of causality. Also, ours was a study of repeat mammography for insured women in their 40s who reported recent mammograms. Factors associated with repeat mammography use for this population might not be generalized to women who are uninsured, never had mammograms or differ demographically from our sample. Our findings cannot be generalized to minority women other than Black women, because there were too few ethnic and racial minority women in the sample to analyze their data. Study participation of Black women and other ethnic groups was lower than predicted. Previous published analyses on rates of non-response found only slight differential non-response by race [66
]. Lower participation of Black women in our study may be a consequence of eligibility criteria that required adherence to a recent mammogram eight to nine months before study entry. Also, while our outcome was annual mammography use, it is unknown if findings would differ had we examined other screening intervals (i.e. biennial screening). We measured history of abnormal mammograms with one item and family history with two items. While not ideal, we were constrained by limitations of telephone interviews.
With these limitations in mind, the results contribute to understanding annual-interval mammography use for women in their 40s, a group that has had substantially less research attention to date. Persistent confusion about the need for mammograms for women in their 40s should be addressed, along with strategies to help women who report they are too busy or forget to make mammograms a priority. Systems-level interventions, such as regular reminders, have been shown definitively to improve adherence to screening [64
]. Special attention should be paid to women who may perceive themselves at lower risk due to not having a family history of breast cancer or not having experienced an abnormal result. Insurance coverage is necessary but not sufficient to assure regular mammography use. Although mammography use has been an accepted medical screening tool for many years, utilization is still sub-optimal, and mammography is still not a habit of most U.S. women.