Discussion
Although there have been significant increases in use of screening mammography during the last decade,3-4,8,10,11 at least 40% of the women in the United States are not adherent to the recommended guidelines. This is an important problem, because regular screening is needed to yield maximal breast cancer mortality reductions.
All of the participants in our study were in age categories for which there are mammography recommendations. It is noteworthy that even though all of the women in our study had insurance covering mammography and were in a plan that actively promoted screening, approximately half were either off schedule or never had a mammogram. This is consistent with the findings of other studies that financial coverage is necessary but not sufficient for mammography use.19
Several provider-related factors were significantly associated with the screening group; off-schedule women were less likely than their on-schedule counterparts but more likely than the never-had group to report having a regular physician, a discussion of mammography with their physicians, or a mammography recommendation from a physician within the past 2 years. The relationship between physician discussion and recommendations could be bidirectional, in that on-schedule women may be more open to discussion or at least perceived by their physicians to be so. They may even be more likely to initiate such discussions. Previous research20 has shown that physician recommendations facilitate adherence. Our data further support the important role of physician discussion and recommendations in repeat adherence. Thus, physicians should continue to reinforce the importance of mammography even for women who have been on schedule.
Although the majority of women in our study knew that mammograms are effective in reducing breast cancer mortality, there were differences by group in knowledge. Women who never had a mammogram were less likely to report that mammograms are effective. Off-schedule women were less knowledgeable than either the on-schedule or never-had groups about how often women should be screened; perhaps this lack of knowledge about when to be rescreened contributes to their being off schedule. In any case, it is important for the physician to remind a woman about the appropriate schedule and to provide a referral.
Off-schedule women were more likely than on-schedule women to be ambivalent about mammography and confused about screening guidelines. Whether these findings can be attributed to the guideline debate of 1997 shortly before our data collection cannot be determined. However, these findings do indicate a need for mammography education about both the rationale for repeat screening and specific information about recommended guidelines.
There is increased interest in evaluating multiple risk behaviors. Our results confirm other findings21-24 that women who are off schedule for mammography are less likely to be adherent for other screening behaviors. Consistent with other studies,21,25-27 we found smokers were less likely to be on schedule for screening mammography. These findings suggest that it may be useful to address multiple screening behaviors rather than focusing on one test at a time.
There were associations between mammography history and variables related to HRT. Consistent with other research,28 off-schedule women were less likely to have ever used or to currently be using HRT. Because it is likely that physicians routinely order mammograms before prescribing HRT, this association may be due more to routine medical procedure than patient characteristics.29 However, whether decisions to use HRT and to have regular mammograms are associated should be explored.
Also consistent with previous findings,7,8 multivariate analyses revealed that younger age, having a CBE within the past 12 months, and physician recommendations were important factors associated with repeat mammography. As previously reported,13 “feeling torn” about mammography and being confused about screening guidelines were negatively associated with being on schedule for mammography.
Limitations
One limitation of our study is that our sample was drawn from women with health insurance rather than from the general population. Thus, we cannot generalize the results of our study to the entire population of North Carolina.
Also, because the sample was drawn for the purposes of a subsequent intervention, there are some other anomalies. We stratified the sample on the basis of age and adherence status, and thus the proportions per se cannot be generalized to the health plan.
Another limitation is that we collected self-report information only on the 2 most recent mammograms. Although long-term mammography history studies should be conducted in the future, ours is one of only a few studies to date that assessed more than 1-time mammography use. Thus, our findings set the stage for future assessments of repeat adherence. Previous research suggests that the correspondence between self-report and mammography use is very high in health maintenance organization settings,30,31 but there is a discrepancy in recall of timing of the mammogram.32 Although we cannot conclusively verify the date of last and previous mammograms, our findings show expected differences between those who reported being on versus off schedule. The 3-month window we allowed before categorizing women as off schedule may have limited misclassification of adherent women as nonadherent. Thus, we probably underestimated the number of women who were off schedule for repeat mammography.