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METHODS: Our data are from a baseline telephone interview conducted among 1287 female members of Blue Cross Blue Shield of North Carolina who were aged either 40 to 44 years or 50 to 54 years.
RESULTS: The 3 groups differed significantly on beliefs and health-related behaviors, with the off-schedule group almost consistently falling between the on-schedule and never screened groups. Off-schedule women were more likely than on-schedule women, but less likely than those never screened, to not have a clinical breast examination within 12 months, to be ambivalent about screening mammography, to be confused about screening guidelines, and to not be advised by a physician to get a mammogram in the past 2 years. Off-schedule women perceived their breast cancer risk as lower and were less likely to be up to date with other cancer screening tests.
CONCLUSIONS: Our findings suggest that women who are off schedule are in need of mammography-promoting interventions, including recommendations from and discussion with their health care providers. Because they are more positive and knowledgeable about mammography than women who have never been screened, they may benefit from brief interventions from health care providers that highlight the importance of repeat screening.
Because most research has shown that routine mammography screening saves lives,1,2 many medical organizations have developed guidelines and recommendations for mammography screening. For example, the National Cancer Institute (NCI) recommends mammograms every 1 to 2 years for women aged 40 years and older and annual screening for women aged 50 years and older. Other organizations, such as the United States Preventive Health Task Force and the American College of Preventive Medicine, differ from the NCI regarding optimal screening intervals, but all agree on the importance of regular screening to achieve a breast cancer mortality reduction benefit.
However, despite these recommendations and substantial increases in the percentage of women who have ever had mammograms, most women are not having regular screening at recommended intervals. There is also still a group of women who have never been screened.3-6 For the purpose of developing interventions to encourage routine screening, it may be important to understand differences among women who are and are not getting repeat screening and those who have never been screened. However, with a few exceptions,7-12 most mammography studies have focused on 1-time screening rather than repeat adherence. Few studies have identified factors that predict repeat mammography use according to recommended guidelines.
For our analysis we sought to better understand factors that differentiate 3 groups of insured women: those who have been screened and are adherent to the screening mammography guidelines of the NCI, those screened at least once but who are currently nonadherent, and those never screened. Study findings should guide the design of interventions to promote continued adherence for repeat screening mammography.
Methods
Study Population
We randomly selected 2165 women from a sampling frame of 4000 women aged 40 to 44 years and 50 to 54 years who were members of the Personal Care Plan of Blue Cross Blue Shield of North Carolina (BCBS of NC) in 1997. We stratified the sample by age and mammography compliance status. Women with previous breast cancer and those who were no longer BCBS members were excluded from the sample. The completion rate for the telephone interviews was 76%, and the nonresponse rate was 20%, leaving a sample of 1287 women.
We mailed introductory letters, and professional interviewers conducted telephone interviews between November 1997 and May 1998. The participants provided oral consent in accordance with regulations from the Department of Health and Human Services. The analyses reported in this paper were conducted on baseline data collected for a larger intervention trial designed to enhance informed decision making about mammography. Additional details regarding our study methodology have been published elsewhere.13
Measures
Screening History Measure. The main variable of interest was self-reported mammography history (including most recent and previous mammograms). We calculated 2 screening variables reflecting whether: (1) the most recent mammogram was within the recommended time frame according to NCI recommendations, and (2) the interval between the most recent and the previous mammography date was within the recommended time frame for the woman’s age. The second interval could be computed only for women with more than 1 previous mammogram.
We categorized the participants as “never had a mammogram,” “off schedule,” or “on schedule for their 2 most recent mammograms.” (We refer to the groups as never had, off schedule, and on schedule.)
We followed the recommendations of BCBS of NC which specified mammography consistent with the NCI recommendation: every 1 to 2 years for women in their 40s and every year for women in their 50s.14 However, because many women are not screened exactly 12 months following their previous mammogram, we added a 3-month window to the intervals; thus, the window was 15 months for women in their 50s and 27 months for women in their 40s. These interval windows are consistent with those adopted by other investigators.10
Our on- and off-schedule classification algorithms allow for women in their early 50s who passed from the “every 1 to 2 years” to the “every year” guidelines between their most recent and previous mammograms and those in their 40s who had not yet had time for 2 mammograms based on their age and the recommendations. The classification of women by screening mammography history is presented in Table 1
Because NCI recommendations indicate a single mammogram for average-risk women younger than 42 years, we could not consider women younger than this to be off schedule, so we excluded them (n=198) from our analysis. Women who had 2 mammograms within 11 months (n=32) were also excluded, because it is likely they were on diagnostic rather than screening schedules. The final analysis was based on 1057 women.
Information From the Telephone Interviews. The sociodemographics included age, ethnic background, educational level, marital status, employment, and financial status.
Medical and family history included whether the woman ever had an abnormal mammogram, a biopsy, or a first-degree relative with breast cancer.
Provider-related measures assessed whether the woman had a regular physician and a provider recommendation for mammography and whether she discussed decisions with her care providers.
Breast cancer screening measures assessed mammography and clinical breast examinations (CBE) using questions asked by the Breast Cancer Screening Consortium of the NCI.15
Other health-related behaviors included when women had their most recent cervical screening, if they exercised regularly (if so, how often), whether they smoked (if so, how frequently), and whether they had thought about, had ever used, and were currently using hormonal replacement therapy (HRT).
Mammography knowledge, beliefs, and perceptions included whether mammograms are effective for reducing breast cancer deaths, how often a woman should be screened, and at what age a woman is more likely to develop breast cancer. In addition, women were asked whether they agreed, disagreed, or were undecided about 20 statements (11 pro and 9 con) about mammography screening consistent with the Transtheoretical model.16,17 The 11 pro and 9 con statements were used to compute pro and con scores, respectively. A high pro score indicates positive beliefs about mammography, while a high con score indicates negative beliefs. Previous research indicates that women who have more pros are more likely to get regular screening mammograms.
Risk perception measures assessed perceived absolute and comparative (self vs other) breast cancer risks. The absolute risk questions included: “How likely are you to get breast cancer in (a) the next 10 years and (b) your lifetime?” Responses were on a 5-point scale from “very unlikely” to “very likely.” For comparative risk the women were asked, “Compared with other women your age, how likely are you to get breast cancer in (a) the next 10 years and (b) your lifetime?” Responses were on a 5-point scale from “much below” to “much above average.”
Worry about breast cancer was measured for the next 10 years and a woman’s lifetime. Five responses ranged from not at all to very worried.
The women were also asked whether they felt ambivalent about getting a mammogram within their age-specific recommended time frames. The responses were agree, disagree, and undecided.
Statistical Analysis
We used the Pearson chi-square test to compare differences in the never-had, off-schedule, and on-schedule groups on provider-related information about mammography screening, women’s mammography knowledge, risk perceptions, worry about breast cancer, ambivalence, and other health-related behaviors. In addition, we used the F test to compare differences in perceived pro and con scales in the 3 groups. Because we were testing several hypotheses, all tests were performed using a 2-sided a=0.01.18
Because we were interested in identifying factors that are associated with repeat mammography use and because the proportional odds assumption was violated, women who never had a mammogram were excluded from the logistic regression analysis. The same results were observed when the never-had group was included with the off-schedule group (data not shown). In a logistic regression analysis modeling the probability of being off schedule, candidate variables were those that had a P value less than or equal to .20 in bivariate analyses Table 2
Table 3. Variables retained in the final model were those significant at a P value less than or equal to .01 level. We calculated odds ratios and 95% confidence intervals for independent variables in the model.
Results
Demographic and Medical History Factors
Seventy-four percent of the participants had more than a high school education. Eighty-two percent were white Table 2. The majority were married (78%), worked for pay (89%), and reported adequate income (91%).
One fourth reported a previous abnormal mammogram; 13% reported at least 1 biopsy; and 9% reported a first-degree relative with breast cancer.
Off-schedule women were less likely than those who were on schedule to report first-degree relatives with breast cancer, previous abnormal mammograms, and breast biopsies.
Provider-Related Information and Knowledge About Screening
The majority of women reported having a regular physician who recommended a mammogram within the past 2 years Table 2. Although most reported that they shared in medical testing decisions with their physicians, only 12% reported having raised questions about breast cancer screening with their physicians during the past 2 years. Off-schedule women were less likely than those on schedule to report having a regular physician and receiving a mammography recommendation in the past 2 years. Off-schedule women were more likely to report these factors than those never screened.
Almost all women reported that they believed mammograms to be effective in reducing breast cancer deaths, but women who were on and off schedule were more likely to do so than the never-had group. Off-schedule women were less likely than the on-schedule and never-had groups to correctly report screening recommendations for women their age.
Risk Perceptions
Comparative risk perceptions were associated with mammography history Table 2. Women who never had a mammogram perceived their comparative risk as lower than those in the on- and off-schedule groups, with off-schedule women falling between the never-had and on-schedule groups.
Perceptions About Mammography
The 3 groups of women differed significantly in perceptions about mammography Table 2. Off-schedule women were more likely than on-schedule women, but less likely than the never-had group, to be ambivalent about mammography and confused about guidelines. Off-schedule women were less likely than on-schedule women to report insufficient information to decide to get a mammogram, but were also more likely than the never-had group to report enough information.
Pro and con mammography scores, which reflected women’s positive and negative beliefs about mammography screening and the likelihood of being screened, were associated with their mammography history (data not shown). The off-schedule group had a significantly lower mean pro score (mean=9.4, standard deviation [SD] =2.4) than on-schedule women (mean=10, SD=1.5), but had a significantly higher mean pro score than the never-had group (mean=7.7, SD=3.6, P <.001). The off-schedule group had a significantly higher mean con score (mean=-5.5, SD=3.1) than on-schedule women (mean=-6.3, SD=2.7), but had a significantly lower mean con score than the never-had group (mean=-3.7, SD=3.6, P <.001).
Screening and Other Health-Related Behaviors
Overall, the majority of the women reported recent CBEs and Papanicolaou (Pap) tests. Approximately half said they got regular exercise and had used HRT Table 3.
Recent CBE and Pap tests were associated with mammography history. Off-schedule women were less likely than those who were on schedule but more likely than the never-had group to report both having a CBE within the past 12 months and a Pap test within 24 months. This pattern persisted among younger (42 to 45 years) and older (50 to 55 years) women.
Previous and current HRT use were associated with mammography history for women aged 50 years and older. Off-schedule women were less likely than on-schedule women, but more likely than women who never had a mammogram, to have used HRT.
Cigarette smoking was associated with mammography history. Women who never had mammograms were more likely to be current smokers than those in the on- and off-schedule groups.
We tested whether women off schedule for mammography were also off schedule for CBEs and cervical screening Table 4. Women who had a CBE within the past 12 months and a Pap test within the past 24 months were considered on schedule for both tests. A chi-square test of trend (P <.001) revealed a strong relationship between being on schedule for mammography screening and being on schedule for CBE and cervical screening.
Multivariate Analysis
Important factors associated with being off schedule for screening mammography were: being aged 50 to 54 years, not having a CBE within the past 12 months, being ambivalent about mammography, low perception of breast cancer risk, not being advised to have a mammogram by a physician in the past 2 years, confusion about screening mammography, and never having an abnormal mammogram Table 5.
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.
Conclusions
Our study is one of a small number to analyze differences in beliefs and other health-related behaviors among groups of women who are on schedule or off schedule for a mamogram and those who never had mammograms. With a few exceptions, the results suggest a trend, as the off-schedule group almost consistently falls between the on-schedule and never-had groups. For instance, they were more likely than those never screened but less likely than on-schedule women to report the kind of provider support (discussions and recommendations) that facilitates screening and to understand the rationale and recommendations for regular screening. Off-schedule women also showed a need to change other health-related behaviors. Off-schedule women were also likely to perceive their breast cancer risk as lower, be less likely to be up to date with other cancer screening tests, and to have ever used HRT.
Because there are few studies comparing women who are on versus off schedule for their 2 most recent mammograms, we were not sure how, for instance, the off-schedule and the never-had group would compare. Our findings suggest that women who are off schedule are in need of mammography-promoting interventions, including recommendations from and discussion with their health care providers. Because they are more positive and knowledgeable about mammography than never screened women, they may benefit from brief interventions from health care providers that highlight the importance of regular screening.
Significant progress has been made in the proportion of women in the United States who have been screened. Further increases will be dependent not only on motivating women who have never been screened but also in enhancing levels of regular screening. Physicians have a central role to play in facilitating regular screening.
Acknowledgments
Our study was funded by the National Cancer Institute grant #5U19-CA-72099-03. We express our sincere appreciation to Don Bradley, MD, at Blue Cross Blue Shield of North Carolina for his leadership and the many women who are participating in this project. We thank Elizabeth Powell for the preparation of the manuscript. Our manuscript represents the perspective of the authors and not the National Cancer Institute.
Related resources
- National Cancer Institute Cancer information, news on research, funding and treatment recommendations. www.nci.nih.gov
- American Cancer Society News on cancer research. Search function identifies local resources. News on breast and other cancers. Information on ACS research and funding programs. Yearly statistics on incidence of cancer dating back to 1995. www.cancer.org
1. Baker LH. Breast cancer detection demonstration project: five-year summary report. Cancer 2. 1982;32:194-225
2. Shapiro S, Venet W, Strax P, Venet L, Roeser R. Ten-to-fourteen year effect of screening on breast cancer mortality. J Natl Cancer Inst 1982;69:349-55
3. Anonymous. Self-reported use of mammography and insurance status among women aged Ž 40 years—United States, 1991-1992 and 1996-1997. MMWR Morb Mortal Wkly Rep 1998;47:825-30
4. Anonymous. Self-reported use of mammography among women aged Ž40 years—United States, 1989 and 1995. MMWR Morb Mortal Wkly Rep 1997;46:937-41
5. Faulkner LA, Schauffler HH. The effect of health insurance coverage on the appropriate use of recommended clinical preventive services. Am J Prev Med 1997;13:453-58
6. Hahn RA, Teutsch SM, Franks AL, Chang MH, Lloyd EE. The prevalence of risk factors among women in the United States by race and age, 1992-1994: opportunities for primary and secondary prevention. J Am Med Womens Assoc 1998;53:96-104,107.
7. Lerman C, Rimer B, Trock B, Balshem A, Engstrom P. Factors associated with repeat adherence to breast cancer screening. Prev Med 1990;19:279-90
8. Bastani R, Kaplan CP, Maxwell AE, Nisenbaum R, Pearce J, Marcus AC. Initial and repeat mammography screening in a low income population in Los Angeles. Cancer Epidemiol Biomarkers Prev 1995;4:161-71.
9. Burack RC, Gimotty PA. Promoting screening mammography in inner-city settings: the sustained effectiveness of computerized reminders in a randomized controlled trial. Med Care 1997;35:921-31
10. Song L, Fletcher R. Breast cancer rescreening in low-income women. Am J Prev Med 1998;15:128-33
11. Yood MU, McCarthy BD, Lee NC, Jacobsen G, Johnson CC. Patterns and characteristics of repeat mammography among women 50 years and older. Cancer Epidemiol Biomarkers Prev 1999;8:595-99
12. Lipkus IM, Rimer BK, Halabi S, Strigo TS. Can tailored interventions increase mammography use among HMO women? Am J Prev Med 2000;18:1-10
13. Rimer BK, Halabi S, Strigo TS, Crawford Y, Lipkus IM. Confusion about mammography: prevalence and consequences. J Women’s Health Gender-Based Med 1999;8:509-20
14. National Cancer Institute and American Cancer Society. Joint statement on breast cancer screening for women in their 40s. The Cancer Information Service; 1997.
15. Stoddard AM, Rimer BK, Lane D, et al. for the NCI Breast Cancer Consortium. Underusers of mammogram screening: stage of adoption in five US subpopulations. Prev Med 1998;27:478-87
16. Rakowski W, Ehrich B, Golsetin M, et al. A stage-matched intervention for screening mammography. Ann Behav Med 1997;19:S063.-
17. Velicer W, DiClemente C, Prochaska J, et al. A decisional balance measure for assessing and predicting smoking status. J Personality Soc Psychol 1985;48:1279-89
18. Forthofer RN, Lehnen RF. Public program analysis: a new categorical data analysis approach. Belmont: Lifetime Learning Publications; 1981.
19. Rimer BK, Resch N, King E, et al. Multistrategy health education program to increase mammography use among women ages 65 and older. Public Health Rep 1992;107:369-80
20. Skinner, Strecher, Hospers. Physicians’ recommendations for mammography: do tailored messages make a difference? Am J Public Health 1994;84:43-49
21. Ronco G, Segnan N, Ponti A. Who has Pap tests? Variables associated with the use of Pap tests in absence of screening programmes. Int J Epidemiol 1991;20:349-53
22. Rakowski W, Rimer BK, Bryant SA. Integrating behavior and intention regarding mammography by respondents in the 1990 national health interview survey of health promotion and disease prevention. Pub Health Reports 1993;108:605-24
23. Hyman RB, Greewald ES, Hacker S. Smoking, dietary, and breast and cervical cancer screening knowledge and screening practices of employees in an urban medical center. J Cancer Educ 1995;10:82-87
24. Pearlman DN, Rakowski W, Ehrich B. Mammography, clinical breast exam and Pap testing: correlates of combined screening. Am J Prev Med 1996;12:52-64
25. Orleans CT, Rimer BK, Cristinzio S, Keintz MK, Fleisher L. A national survey of older smokers: treatment needs of a growing population. Health Psychol 1991;10:343-51.
26. McBride CM, Curry SJ, Taplin S, Anderman C, Grothaus L. Exploring environmental barriers to participation in mammography screening in an HMO. Can Epidemiol Biomarkers Prev 1993;2:559-605
27. Beaulieu MD, Beland F, Roy D, Falardeau M, Herbert G. Factors determining compliance with screening mammography. Can Med Assoc J 1996;154:1335-43
28. Bastian LA, Couchman GM, Rimer BK, McBride CM, Feaganes JR, Siegler IC. Perceptions of menopausal stage and patterns of hormone replacement therapy use. J Women’s Health 1997;6:467-75
29. Personal communication with Lori Bastian.
30. King ES, Rimer BK, Trock B, Balshem A, Engstrom P. How valid are mammography self-reports? Am J Public Health 1990;80:1386-88
31. Degnan D, Harris R, Ranney J, Quade D, Earp JA, Gonzalez J. Measuring the use of mammography: two methods compared. Am J Public Health 1992;82:1386-88
32. PM, Mickey RM, Worden JK. Reliability of self-reported breast screening information in a survey of lower income women. Prev Med 1997;26:287-91
METHODS: Our data are from a baseline telephone interview conducted among 1287 female members of Blue Cross Blue Shield of North Carolina who were aged either 40 to 44 years or 50 to 54 years.
RESULTS: The 3 groups differed significantly on beliefs and health-related behaviors, with the off-schedule group almost consistently falling between the on-schedule and never screened groups. Off-schedule women were more likely than on-schedule women, but less likely than those never screened, to not have a clinical breast examination within 12 months, to be ambivalent about screening mammography, to be confused about screening guidelines, and to not be advised by a physician to get a mammogram in the past 2 years. Off-schedule women perceived their breast cancer risk as lower and were less likely to be up to date with other cancer screening tests.
CONCLUSIONS: Our findings suggest that women who are off schedule are in need of mammography-promoting interventions, including recommendations from and discussion with their health care providers. Because they are more positive and knowledgeable about mammography than women who have never been screened, they may benefit from brief interventions from health care providers that highlight the importance of repeat screening.
Because most research has shown that routine mammography screening saves lives,1,2 many medical organizations have developed guidelines and recommendations for mammography screening. For example, the National Cancer Institute (NCI) recommends mammograms every 1 to 2 years for women aged 40 years and older and annual screening for women aged 50 years and older. Other organizations, such as the United States Preventive Health Task Force and the American College of Preventive Medicine, differ from the NCI regarding optimal screening intervals, but all agree on the importance of regular screening to achieve a breast cancer mortality reduction benefit.
However, despite these recommendations and substantial increases in the percentage of women who have ever had mammograms, most women are not having regular screening at recommended intervals. There is also still a group of women who have never been screened.3-6 For the purpose of developing interventions to encourage routine screening, it may be important to understand differences among women who are and are not getting repeat screening and those who have never been screened. However, with a few exceptions,7-12 most mammography studies have focused on 1-time screening rather than repeat adherence. Few studies have identified factors that predict repeat mammography use according to recommended guidelines.
For our analysis we sought to better understand factors that differentiate 3 groups of insured women: those who have been screened and are adherent to the screening mammography guidelines of the NCI, those screened at least once but who are currently nonadherent, and those never screened. Study findings should guide the design of interventions to promote continued adherence for repeat screening mammography.
Methods
Study Population
We randomly selected 2165 women from a sampling frame of 4000 women aged 40 to 44 years and 50 to 54 years who were members of the Personal Care Plan of Blue Cross Blue Shield of North Carolina (BCBS of NC) in 1997. We stratified the sample by age and mammography compliance status. Women with previous breast cancer and those who were no longer BCBS members were excluded from the sample. The completion rate for the telephone interviews was 76%, and the nonresponse rate was 20%, leaving a sample of 1287 women.
We mailed introductory letters, and professional interviewers conducted telephone interviews between November 1997 and May 1998. The participants provided oral consent in accordance with regulations from the Department of Health and Human Services. The analyses reported in this paper were conducted on baseline data collected for a larger intervention trial designed to enhance informed decision making about mammography. Additional details regarding our study methodology have been published elsewhere.13
Measures
Screening History Measure. The main variable of interest was self-reported mammography history (including most recent and previous mammograms). We calculated 2 screening variables reflecting whether: (1) the most recent mammogram was within the recommended time frame according to NCI recommendations, and (2) the interval between the most recent and the previous mammography date was within the recommended time frame for the woman’s age. The second interval could be computed only for women with more than 1 previous mammogram.
We categorized the participants as “never had a mammogram,” “off schedule,” or “on schedule for their 2 most recent mammograms.” (We refer to the groups as never had, off schedule, and on schedule.)
We followed the recommendations of BCBS of NC which specified mammography consistent with the NCI recommendation: every 1 to 2 years for women in their 40s and every year for women in their 50s.14 However, because many women are not screened exactly 12 months following their previous mammogram, we added a 3-month window to the intervals; thus, the window was 15 months for women in their 50s and 27 months for women in their 40s. These interval windows are consistent with those adopted by other investigators.10
Our on- and off-schedule classification algorithms allow for women in their early 50s who passed from the “every 1 to 2 years” to the “every year” guidelines between their most recent and previous mammograms and those in their 40s who had not yet had time for 2 mammograms based on their age and the recommendations. The classification of women by screening mammography history is presented in Table 1
Because NCI recommendations indicate a single mammogram for average-risk women younger than 42 years, we could not consider women younger than this to be off schedule, so we excluded them (n=198) from our analysis. Women who had 2 mammograms within 11 months (n=32) were also excluded, because it is likely they were on diagnostic rather than screening schedules. The final analysis was based on 1057 women.
Information From the Telephone Interviews. The sociodemographics included age, ethnic background, educational level, marital status, employment, and financial status.
Medical and family history included whether the woman ever had an abnormal mammogram, a biopsy, or a first-degree relative with breast cancer.
Provider-related measures assessed whether the woman had a regular physician and a provider recommendation for mammography and whether she discussed decisions with her care providers.
Breast cancer screening measures assessed mammography and clinical breast examinations (CBE) using questions asked by the Breast Cancer Screening Consortium of the NCI.15
Other health-related behaviors included when women had their most recent cervical screening, if they exercised regularly (if so, how often), whether they smoked (if so, how frequently), and whether they had thought about, had ever used, and were currently using hormonal replacement therapy (HRT).
Mammography knowledge, beliefs, and perceptions included whether mammograms are effective for reducing breast cancer deaths, how often a woman should be screened, and at what age a woman is more likely to develop breast cancer. In addition, women were asked whether they agreed, disagreed, or were undecided about 20 statements (11 pro and 9 con) about mammography screening consistent with the Transtheoretical model.16,17 The 11 pro and 9 con statements were used to compute pro and con scores, respectively. A high pro score indicates positive beliefs about mammography, while a high con score indicates negative beliefs. Previous research indicates that women who have more pros are more likely to get regular screening mammograms.
Risk perception measures assessed perceived absolute and comparative (self vs other) breast cancer risks. The absolute risk questions included: “How likely are you to get breast cancer in (a) the next 10 years and (b) your lifetime?” Responses were on a 5-point scale from “very unlikely” to “very likely.” For comparative risk the women were asked, “Compared with other women your age, how likely are you to get breast cancer in (a) the next 10 years and (b) your lifetime?” Responses were on a 5-point scale from “much below” to “much above average.”
Worry about breast cancer was measured for the next 10 years and a woman’s lifetime. Five responses ranged from not at all to very worried.
The women were also asked whether they felt ambivalent about getting a mammogram within their age-specific recommended time frames. The responses were agree, disagree, and undecided.
Statistical Analysis
We used the Pearson chi-square test to compare differences in the never-had, off-schedule, and on-schedule groups on provider-related information about mammography screening, women’s mammography knowledge, risk perceptions, worry about breast cancer, ambivalence, and other health-related behaviors. In addition, we used the F test to compare differences in perceived pro and con scales in the 3 groups. Because we were testing several hypotheses, all tests were performed using a 2-sided a=0.01.18
Because we were interested in identifying factors that are associated with repeat mammography use and because the proportional odds assumption was violated, women who never had a mammogram were excluded from the logistic regression analysis. The same results were observed when the never-had group was included with the off-schedule group (data not shown). In a logistic regression analysis modeling the probability of being off schedule, candidate variables were those that had a P value less than or equal to .20 in bivariate analyses Table 2
Table 3. Variables retained in the final model were those significant at a P value less than or equal to .01 level. We calculated odds ratios and 95% confidence intervals for independent variables in the model.
Results
Demographic and Medical History Factors
Seventy-four percent of the participants had more than a high school education. Eighty-two percent were white Table 2. The majority were married (78%), worked for pay (89%), and reported adequate income (91%).
One fourth reported a previous abnormal mammogram; 13% reported at least 1 biopsy; and 9% reported a first-degree relative with breast cancer.
Off-schedule women were less likely than those who were on schedule to report first-degree relatives with breast cancer, previous abnormal mammograms, and breast biopsies.
Provider-Related Information and Knowledge About Screening
The majority of women reported having a regular physician who recommended a mammogram within the past 2 years Table 2. Although most reported that they shared in medical testing decisions with their physicians, only 12% reported having raised questions about breast cancer screening with their physicians during the past 2 years. Off-schedule women were less likely than those on schedule to report having a regular physician and receiving a mammography recommendation in the past 2 years. Off-schedule women were more likely to report these factors than those never screened.
Almost all women reported that they believed mammograms to be effective in reducing breast cancer deaths, but women who were on and off schedule were more likely to do so than the never-had group. Off-schedule women were less likely than the on-schedule and never-had groups to correctly report screening recommendations for women their age.
Risk Perceptions
Comparative risk perceptions were associated with mammography history Table 2. Women who never had a mammogram perceived their comparative risk as lower than those in the on- and off-schedule groups, with off-schedule women falling between the never-had and on-schedule groups.
Perceptions About Mammography
The 3 groups of women differed significantly in perceptions about mammography Table 2. Off-schedule women were more likely than on-schedule women, but less likely than the never-had group, to be ambivalent about mammography and confused about guidelines. Off-schedule women were less likely than on-schedule women to report insufficient information to decide to get a mammogram, but were also more likely than the never-had group to report enough information.
Pro and con mammography scores, which reflected women’s positive and negative beliefs about mammography screening and the likelihood of being screened, were associated with their mammography history (data not shown). The off-schedule group had a significantly lower mean pro score (mean=9.4, standard deviation [SD] =2.4) than on-schedule women (mean=10, SD=1.5), but had a significantly higher mean pro score than the never-had group (mean=7.7, SD=3.6, P <.001). The off-schedule group had a significantly higher mean con score (mean=-5.5, SD=3.1) than on-schedule women (mean=-6.3, SD=2.7), but had a significantly lower mean con score than the never-had group (mean=-3.7, SD=3.6, P <.001).
Screening and Other Health-Related Behaviors
Overall, the majority of the women reported recent CBEs and Papanicolaou (Pap) tests. Approximately half said they got regular exercise and had used HRT Table 3.
Recent CBE and Pap tests were associated with mammography history. Off-schedule women were less likely than those who were on schedule but more likely than the never-had group to report both having a CBE within the past 12 months and a Pap test within 24 months. This pattern persisted among younger (42 to 45 years) and older (50 to 55 years) women.
Previous and current HRT use were associated with mammography history for women aged 50 years and older. Off-schedule women were less likely than on-schedule women, but more likely than women who never had a mammogram, to have used HRT.
Cigarette smoking was associated with mammography history. Women who never had mammograms were more likely to be current smokers than those in the on- and off-schedule groups.
We tested whether women off schedule for mammography were also off schedule for CBEs and cervical screening Table 4. Women who had a CBE within the past 12 months and a Pap test within the past 24 months were considered on schedule for both tests. A chi-square test of trend (P <.001) revealed a strong relationship between being on schedule for mammography screening and being on schedule for CBE and cervical screening.
Multivariate Analysis
Important factors associated with being off schedule for screening mammography were: being aged 50 to 54 years, not having a CBE within the past 12 months, being ambivalent about mammography, low perception of breast cancer risk, not being advised to have a mammogram by a physician in the past 2 years, confusion about screening mammography, and never having an abnormal mammogram Table 5.
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.
Conclusions
Our study is one of a small number to analyze differences in beliefs and other health-related behaviors among groups of women who are on schedule or off schedule for a mamogram and those who never had mammograms. With a few exceptions, the results suggest a trend, as the off-schedule group almost consistently falls between the on-schedule and never-had groups. For instance, they were more likely than those never screened but less likely than on-schedule women to report the kind of provider support (discussions and recommendations) that facilitates screening and to understand the rationale and recommendations for regular screening. Off-schedule women also showed a need to change other health-related behaviors. Off-schedule women were also likely to perceive their breast cancer risk as lower, be less likely to be up to date with other cancer screening tests, and to have ever used HRT.
Because there are few studies comparing women who are on versus off schedule for their 2 most recent mammograms, we were not sure how, for instance, the off-schedule and the never-had group would compare. Our findings suggest that women who are off schedule are in need of mammography-promoting interventions, including recommendations from and discussion with their health care providers. Because they are more positive and knowledgeable about mammography than never screened women, they may benefit from brief interventions from health care providers that highlight the importance of regular screening.
Significant progress has been made in the proportion of women in the United States who have been screened. Further increases will be dependent not only on motivating women who have never been screened but also in enhancing levels of regular screening. Physicians have a central role to play in facilitating regular screening.
Acknowledgments
Our study was funded by the National Cancer Institute grant #5U19-CA-72099-03. We express our sincere appreciation to Don Bradley, MD, at Blue Cross Blue Shield of North Carolina for his leadership and the many women who are participating in this project. We thank Elizabeth Powell for the preparation of the manuscript. Our manuscript represents the perspective of the authors and not the National Cancer Institute.
Related resources
- National Cancer Institute Cancer information, news on research, funding and treatment recommendations. www.nci.nih.gov
- American Cancer Society News on cancer research. Search function identifies local resources. News on breast and other cancers. Information on ACS research and funding programs. Yearly statistics on incidence of cancer dating back to 1995. www.cancer.org
METHODS: Our data are from a baseline telephone interview conducted among 1287 female members of Blue Cross Blue Shield of North Carolina who were aged either 40 to 44 years or 50 to 54 years.
RESULTS: The 3 groups differed significantly on beliefs and health-related behaviors, with the off-schedule group almost consistently falling between the on-schedule and never screened groups. Off-schedule women were more likely than on-schedule women, but less likely than those never screened, to not have a clinical breast examination within 12 months, to be ambivalent about screening mammography, to be confused about screening guidelines, and to not be advised by a physician to get a mammogram in the past 2 years. Off-schedule women perceived their breast cancer risk as lower and were less likely to be up to date with other cancer screening tests.
CONCLUSIONS: Our findings suggest that women who are off schedule are in need of mammography-promoting interventions, including recommendations from and discussion with their health care providers. Because they are more positive and knowledgeable about mammography than women who have never been screened, they may benefit from brief interventions from health care providers that highlight the importance of repeat screening.
Because most research has shown that routine mammography screening saves lives,1,2 many medical organizations have developed guidelines and recommendations for mammography screening. For example, the National Cancer Institute (NCI) recommends mammograms every 1 to 2 years for women aged 40 years and older and annual screening for women aged 50 years and older. Other organizations, such as the United States Preventive Health Task Force and the American College of Preventive Medicine, differ from the NCI regarding optimal screening intervals, but all agree on the importance of regular screening to achieve a breast cancer mortality reduction benefit.
However, despite these recommendations and substantial increases in the percentage of women who have ever had mammograms, most women are not having regular screening at recommended intervals. There is also still a group of women who have never been screened.3-6 For the purpose of developing interventions to encourage routine screening, it may be important to understand differences among women who are and are not getting repeat screening and those who have never been screened. However, with a few exceptions,7-12 most mammography studies have focused on 1-time screening rather than repeat adherence. Few studies have identified factors that predict repeat mammography use according to recommended guidelines.
For our analysis we sought to better understand factors that differentiate 3 groups of insured women: those who have been screened and are adherent to the screening mammography guidelines of the NCI, those screened at least once but who are currently nonadherent, and those never screened. Study findings should guide the design of interventions to promote continued adherence for repeat screening mammography.
Methods
Study Population
We randomly selected 2165 women from a sampling frame of 4000 women aged 40 to 44 years and 50 to 54 years who were members of the Personal Care Plan of Blue Cross Blue Shield of North Carolina (BCBS of NC) in 1997. We stratified the sample by age and mammography compliance status. Women with previous breast cancer and those who were no longer BCBS members were excluded from the sample. The completion rate for the telephone interviews was 76%, and the nonresponse rate was 20%, leaving a sample of 1287 women.
We mailed introductory letters, and professional interviewers conducted telephone interviews between November 1997 and May 1998. The participants provided oral consent in accordance with regulations from the Department of Health and Human Services. The analyses reported in this paper were conducted on baseline data collected for a larger intervention trial designed to enhance informed decision making about mammography. Additional details regarding our study methodology have been published elsewhere.13
Measures
Screening History Measure. The main variable of interest was self-reported mammography history (including most recent and previous mammograms). We calculated 2 screening variables reflecting whether: (1) the most recent mammogram was within the recommended time frame according to NCI recommendations, and (2) the interval between the most recent and the previous mammography date was within the recommended time frame for the woman’s age. The second interval could be computed only for women with more than 1 previous mammogram.
We categorized the participants as “never had a mammogram,” “off schedule,” or “on schedule for their 2 most recent mammograms.” (We refer to the groups as never had, off schedule, and on schedule.)
We followed the recommendations of BCBS of NC which specified mammography consistent with the NCI recommendation: every 1 to 2 years for women in their 40s and every year for women in their 50s.14 However, because many women are not screened exactly 12 months following their previous mammogram, we added a 3-month window to the intervals; thus, the window was 15 months for women in their 50s and 27 months for women in their 40s. These interval windows are consistent with those adopted by other investigators.10
Our on- and off-schedule classification algorithms allow for women in their early 50s who passed from the “every 1 to 2 years” to the “every year” guidelines between their most recent and previous mammograms and those in their 40s who had not yet had time for 2 mammograms based on their age and the recommendations. The classification of women by screening mammography history is presented in Table 1
Because NCI recommendations indicate a single mammogram for average-risk women younger than 42 years, we could not consider women younger than this to be off schedule, so we excluded them (n=198) from our analysis. Women who had 2 mammograms within 11 months (n=32) were also excluded, because it is likely they were on diagnostic rather than screening schedules. The final analysis was based on 1057 women.
Information From the Telephone Interviews. The sociodemographics included age, ethnic background, educational level, marital status, employment, and financial status.
Medical and family history included whether the woman ever had an abnormal mammogram, a biopsy, or a first-degree relative with breast cancer.
Provider-related measures assessed whether the woman had a regular physician and a provider recommendation for mammography and whether she discussed decisions with her care providers.
Breast cancer screening measures assessed mammography and clinical breast examinations (CBE) using questions asked by the Breast Cancer Screening Consortium of the NCI.15
Other health-related behaviors included when women had their most recent cervical screening, if they exercised regularly (if so, how often), whether they smoked (if so, how frequently), and whether they had thought about, had ever used, and were currently using hormonal replacement therapy (HRT).
Mammography knowledge, beliefs, and perceptions included whether mammograms are effective for reducing breast cancer deaths, how often a woman should be screened, and at what age a woman is more likely to develop breast cancer. In addition, women were asked whether they agreed, disagreed, or were undecided about 20 statements (11 pro and 9 con) about mammography screening consistent with the Transtheoretical model.16,17 The 11 pro and 9 con statements were used to compute pro and con scores, respectively. A high pro score indicates positive beliefs about mammography, while a high con score indicates negative beliefs. Previous research indicates that women who have more pros are more likely to get regular screening mammograms.
Risk perception measures assessed perceived absolute and comparative (self vs other) breast cancer risks. The absolute risk questions included: “How likely are you to get breast cancer in (a) the next 10 years and (b) your lifetime?” Responses were on a 5-point scale from “very unlikely” to “very likely.” For comparative risk the women were asked, “Compared with other women your age, how likely are you to get breast cancer in (a) the next 10 years and (b) your lifetime?” Responses were on a 5-point scale from “much below” to “much above average.”
Worry about breast cancer was measured for the next 10 years and a woman’s lifetime. Five responses ranged from not at all to very worried.
The women were also asked whether they felt ambivalent about getting a mammogram within their age-specific recommended time frames. The responses were agree, disagree, and undecided.
Statistical Analysis
We used the Pearson chi-square test to compare differences in the never-had, off-schedule, and on-schedule groups on provider-related information about mammography screening, women’s mammography knowledge, risk perceptions, worry about breast cancer, ambivalence, and other health-related behaviors. In addition, we used the F test to compare differences in perceived pro and con scales in the 3 groups. Because we were testing several hypotheses, all tests were performed using a 2-sided a=0.01.18
Because we were interested in identifying factors that are associated with repeat mammography use and because the proportional odds assumption was violated, women who never had a mammogram were excluded from the logistic regression analysis. The same results were observed when the never-had group was included with the off-schedule group (data not shown). In a logistic regression analysis modeling the probability of being off schedule, candidate variables were those that had a P value less than or equal to .20 in bivariate analyses Table 2
Table 3. Variables retained in the final model were those significant at a P value less than or equal to .01 level. We calculated odds ratios and 95% confidence intervals for independent variables in the model.
Results
Demographic and Medical History Factors
Seventy-four percent of the participants had more than a high school education. Eighty-two percent were white Table 2. The majority were married (78%), worked for pay (89%), and reported adequate income (91%).
One fourth reported a previous abnormal mammogram; 13% reported at least 1 biopsy; and 9% reported a first-degree relative with breast cancer.
Off-schedule women were less likely than those who were on schedule to report first-degree relatives with breast cancer, previous abnormal mammograms, and breast biopsies.
Provider-Related Information and Knowledge About Screening
The majority of women reported having a regular physician who recommended a mammogram within the past 2 years Table 2. Although most reported that they shared in medical testing decisions with their physicians, only 12% reported having raised questions about breast cancer screening with their physicians during the past 2 years. Off-schedule women were less likely than those on schedule to report having a regular physician and receiving a mammography recommendation in the past 2 years. Off-schedule women were more likely to report these factors than those never screened.
Almost all women reported that they believed mammograms to be effective in reducing breast cancer deaths, but women who were on and off schedule were more likely to do so than the never-had group. Off-schedule women were less likely than the on-schedule and never-had groups to correctly report screening recommendations for women their age.
Risk Perceptions
Comparative risk perceptions were associated with mammography history Table 2. Women who never had a mammogram perceived their comparative risk as lower than those in the on- and off-schedule groups, with off-schedule women falling between the never-had and on-schedule groups.
Perceptions About Mammography
The 3 groups of women differed significantly in perceptions about mammography Table 2. Off-schedule women were more likely than on-schedule women, but less likely than the never-had group, to be ambivalent about mammography and confused about guidelines. Off-schedule women were less likely than on-schedule women to report insufficient information to decide to get a mammogram, but were also more likely than the never-had group to report enough information.
Pro and con mammography scores, which reflected women’s positive and negative beliefs about mammography screening and the likelihood of being screened, were associated with their mammography history (data not shown). The off-schedule group had a significantly lower mean pro score (mean=9.4, standard deviation [SD] =2.4) than on-schedule women (mean=10, SD=1.5), but had a significantly higher mean pro score than the never-had group (mean=7.7, SD=3.6, P <.001). The off-schedule group had a significantly higher mean con score (mean=-5.5, SD=3.1) than on-schedule women (mean=-6.3, SD=2.7), but had a significantly lower mean con score than the never-had group (mean=-3.7, SD=3.6, P <.001).
Screening and Other Health-Related Behaviors
Overall, the majority of the women reported recent CBEs and Papanicolaou (Pap) tests. Approximately half said they got regular exercise and had used HRT Table 3.
Recent CBE and Pap tests were associated with mammography history. Off-schedule women were less likely than those who were on schedule but more likely than the never-had group to report both having a CBE within the past 12 months and a Pap test within 24 months. This pattern persisted among younger (42 to 45 years) and older (50 to 55 years) women.
Previous and current HRT use were associated with mammography history for women aged 50 years and older. Off-schedule women were less likely than on-schedule women, but more likely than women who never had a mammogram, to have used HRT.
Cigarette smoking was associated with mammography history. Women who never had mammograms were more likely to be current smokers than those in the on- and off-schedule groups.
We tested whether women off schedule for mammography were also off schedule for CBEs and cervical screening Table 4. Women who had a CBE within the past 12 months and a Pap test within the past 24 months were considered on schedule for both tests. A chi-square test of trend (P <.001) revealed a strong relationship between being on schedule for mammography screening and being on schedule for CBE and cervical screening.
Multivariate Analysis
Important factors associated with being off schedule for screening mammography were: being aged 50 to 54 years, not having a CBE within the past 12 months, being ambivalent about mammography, low perception of breast cancer risk, not being advised to have a mammogram by a physician in the past 2 years, confusion about screening mammography, and never having an abnormal mammogram Table 5.
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.
Conclusions
Our study is one of a small number to analyze differences in beliefs and other health-related behaviors among groups of women who are on schedule or off schedule for a mamogram and those who never had mammograms. With a few exceptions, the results suggest a trend, as the off-schedule group almost consistently falls between the on-schedule and never-had groups. For instance, they were more likely than those never screened but less likely than on-schedule women to report the kind of provider support (discussions and recommendations) that facilitates screening and to understand the rationale and recommendations for regular screening. Off-schedule women also showed a need to change other health-related behaviors. Off-schedule women were also likely to perceive their breast cancer risk as lower, be less likely to be up to date with other cancer screening tests, and to have ever used HRT.
Because there are few studies comparing women who are on versus off schedule for their 2 most recent mammograms, we were not sure how, for instance, the off-schedule and the never-had group would compare. Our findings suggest that women who are off schedule are in need of mammography-promoting interventions, including recommendations from and discussion with their health care providers. Because they are more positive and knowledgeable about mammography than never screened women, they may benefit from brief interventions from health care providers that highlight the importance of regular screening.
Significant progress has been made in the proportion of women in the United States who have been screened. Further increases will be dependent not only on motivating women who have never been screened but also in enhancing levels of regular screening. Physicians have a central role to play in facilitating regular screening.
Acknowledgments
Our study was funded by the National Cancer Institute grant #5U19-CA-72099-03. We express our sincere appreciation to Don Bradley, MD, at Blue Cross Blue Shield of North Carolina for his leadership and the many women who are participating in this project. We thank Elizabeth Powell for the preparation of the manuscript. Our manuscript represents the perspective of the authors and not the National Cancer Institute.
Related resources
- National Cancer Institute Cancer information, news on research, funding and treatment recommendations. www.nci.nih.gov
- American Cancer Society News on cancer research. Search function identifies local resources. News on breast and other cancers. Information on ACS research and funding programs. Yearly statistics on incidence of cancer dating back to 1995. www.cancer.org
1. Baker LH. Breast cancer detection demonstration project: five-year summary report. Cancer 2. 1982;32:194-225
2. Shapiro S, Venet W, Strax P, Venet L, Roeser R. Ten-to-fourteen year effect of screening on breast cancer mortality. J Natl Cancer Inst 1982;69:349-55
3. Anonymous. Self-reported use of mammography and insurance status among women aged Ž 40 years—United States, 1991-1992 and 1996-1997. MMWR Morb Mortal Wkly Rep 1998;47:825-30
4. Anonymous. Self-reported use of mammography among women aged Ž40 years—United States, 1989 and 1995. MMWR Morb Mortal Wkly Rep 1997;46:937-41
5. Faulkner LA, Schauffler HH. The effect of health insurance coverage on the appropriate use of recommended clinical preventive services. Am J Prev Med 1997;13:453-58
6. Hahn RA, Teutsch SM, Franks AL, Chang MH, Lloyd EE. The prevalence of risk factors among women in the United States by race and age, 1992-1994: opportunities for primary and secondary prevention. J Am Med Womens Assoc 1998;53:96-104,107.
7. Lerman C, Rimer B, Trock B, Balshem A, Engstrom P. Factors associated with repeat adherence to breast cancer screening. Prev Med 1990;19:279-90
8. Bastani R, Kaplan CP, Maxwell AE, Nisenbaum R, Pearce J, Marcus AC. Initial and repeat mammography screening in a low income population in Los Angeles. Cancer Epidemiol Biomarkers Prev 1995;4:161-71.
9. Burack RC, Gimotty PA. Promoting screening mammography in inner-city settings: the sustained effectiveness of computerized reminders in a randomized controlled trial. Med Care 1997;35:921-31
10. Song L, Fletcher R. Breast cancer rescreening in low-income women. Am J Prev Med 1998;15:128-33
11. Yood MU, McCarthy BD, Lee NC, Jacobsen G, Johnson CC. Patterns and characteristics of repeat mammography among women 50 years and older. Cancer Epidemiol Biomarkers Prev 1999;8:595-99
12. Lipkus IM, Rimer BK, Halabi S, Strigo TS. Can tailored interventions increase mammography use among HMO women? Am J Prev Med 2000;18:1-10
13. Rimer BK, Halabi S, Strigo TS, Crawford Y, Lipkus IM. Confusion about mammography: prevalence and consequences. J Women’s Health Gender-Based Med 1999;8:509-20
14. National Cancer Institute and American Cancer Society. Joint statement on breast cancer screening for women in their 40s. The Cancer Information Service; 1997.
15. Stoddard AM, Rimer BK, Lane D, et al. for the NCI Breast Cancer Consortium. Underusers of mammogram screening: stage of adoption in five US subpopulations. Prev Med 1998;27:478-87
16. Rakowski W, Ehrich B, Golsetin M, et al. A stage-matched intervention for screening mammography. Ann Behav Med 1997;19:S063.-
17. Velicer W, DiClemente C, Prochaska J, et al. A decisional balance measure for assessing and predicting smoking status. J Personality Soc Psychol 1985;48:1279-89
18. Forthofer RN, Lehnen RF. Public program analysis: a new categorical data analysis approach. Belmont: Lifetime Learning Publications; 1981.
19. Rimer BK, Resch N, King E, et al. Multistrategy health education program to increase mammography use among women ages 65 and older. Public Health Rep 1992;107:369-80
20. Skinner, Strecher, Hospers. Physicians’ recommendations for mammography: do tailored messages make a difference? Am J Public Health 1994;84:43-49
21. Ronco G, Segnan N, Ponti A. Who has Pap tests? Variables associated with the use of Pap tests in absence of screening programmes. Int J Epidemiol 1991;20:349-53
22. Rakowski W, Rimer BK, Bryant SA. Integrating behavior and intention regarding mammography by respondents in the 1990 national health interview survey of health promotion and disease prevention. Pub Health Reports 1993;108:605-24
23. Hyman RB, Greewald ES, Hacker S. Smoking, dietary, and breast and cervical cancer screening knowledge and screening practices of employees in an urban medical center. J Cancer Educ 1995;10:82-87
24. Pearlman DN, Rakowski W, Ehrich B. Mammography, clinical breast exam and Pap testing: correlates of combined screening. Am J Prev Med 1996;12:52-64
25. Orleans CT, Rimer BK, Cristinzio S, Keintz MK, Fleisher L. A national survey of older smokers: treatment needs of a growing population. Health Psychol 1991;10:343-51.
26. McBride CM, Curry SJ, Taplin S, Anderman C, Grothaus L. Exploring environmental barriers to participation in mammography screening in an HMO. Can Epidemiol Biomarkers Prev 1993;2:559-605
27. Beaulieu MD, Beland F, Roy D, Falardeau M, Herbert G. Factors determining compliance with screening mammography. Can Med Assoc J 1996;154:1335-43
28. Bastian LA, Couchman GM, Rimer BK, McBride CM, Feaganes JR, Siegler IC. Perceptions of menopausal stage and patterns of hormone replacement therapy use. J Women’s Health 1997;6:467-75
29. Personal communication with Lori Bastian.
30. King ES, Rimer BK, Trock B, Balshem A, Engstrom P. How valid are mammography self-reports? Am J Public Health 1990;80:1386-88
31. Degnan D, Harris R, Ranney J, Quade D, Earp JA, Gonzalez J. Measuring the use of mammography: two methods compared. Am J Public Health 1992;82:1386-88
32. PM, Mickey RM, Worden JK. Reliability of self-reported breast screening information in a survey of lower income women. Prev Med 1997;26:287-91
1. Baker LH. Breast cancer detection demonstration project: five-year summary report. Cancer 2. 1982;32:194-225
2. Shapiro S, Venet W, Strax P, Venet L, Roeser R. Ten-to-fourteen year effect of screening on breast cancer mortality. J Natl Cancer Inst 1982;69:349-55
3. Anonymous. Self-reported use of mammography and insurance status among women aged Ž 40 years—United States, 1991-1992 and 1996-1997. MMWR Morb Mortal Wkly Rep 1998;47:825-30
4. Anonymous. Self-reported use of mammography among women aged Ž40 years—United States, 1989 and 1995. MMWR Morb Mortal Wkly Rep 1997;46:937-41
5. Faulkner LA, Schauffler HH. The effect of health insurance coverage on the appropriate use of recommended clinical preventive services. Am J Prev Med 1997;13:453-58
6. Hahn RA, Teutsch SM, Franks AL, Chang MH, Lloyd EE. The prevalence of risk factors among women in the United States by race and age, 1992-1994: opportunities for primary and secondary prevention. J Am Med Womens Assoc 1998;53:96-104,107.
7. Lerman C, Rimer B, Trock B, Balshem A, Engstrom P. Factors associated with repeat adherence to breast cancer screening. Prev Med 1990;19:279-90
8. Bastani R, Kaplan CP, Maxwell AE, Nisenbaum R, Pearce J, Marcus AC. Initial and repeat mammography screening in a low income population in Los Angeles. Cancer Epidemiol Biomarkers Prev 1995;4:161-71.
9. Burack RC, Gimotty PA. Promoting screening mammography in inner-city settings: the sustained effectiveness of computerized reminders in a randomized controlled trial. Med Care 1997;35:921-31
10. Song L, Fletcher R. Breast cancer rescreening in low-income women. Am J Prev Med 1998;15:128-33
11. Yood MU, McCarthy BD, Lee NC, Jacobsen G, Johnson CC. Patterns and characteristics of repeat mammography among women 50 years and older. Cancer Epidemiol Biomarkers Prev 1999;8:595-99
12. Lipkus IM, Rimer BK, Halabi S, Strigo TS. Can tailored interventions increase mammography use among HMO women? Am J Prev Med 2000;18:1-10
13. Rimer BK, Halabi S, Strigo TS, Crawford Y, Lipkus IM. Confusion about mammography: prevalence and consequences. J Women’s Health Gender-Based Med 1999;8:509-20
14. National Cancer Institute and American Cancer Society. Joint statement on breast cancer screening for women in their 40s. The Cancer Information Service; 1997.
15. Stoddard AM, Rimer BK, Lane D, et al. for the NCI Breast Cancer Consortium. Underusers of mammogram screening: stage of adoption in five US subpopulations. Prev Med 1998;27:478-87
16. Rakowski W, Ehrich B, Golsetin M, et al. A stage-matched intervention for screening mammography. Ann Behav Med 1997;19:S063.-
17. Velicer W, DiClemente C, Prochaska J, et al. A decisional balance measure for assessing and predicting smoking status. J Personality Soc Psychol 1985;48:1279-89
18. Forthofer RN, Lehnen RF. Public program analysis: a new categorical data analysis approach. Belmont: Lifetime Learning Publications; 1981.
19. Rimer BK, Resch N, King E, et al. Multistrategy health education program to increase mammography use among women ages 65 and older. Public Health Rep 1992;107:369-80
20. Skinner, Strecher, Hospers. Physicians’ recommendations for mammography: do tailored messages make a difference? Am J Public Health 1994;84:43-49
21. Ronco G, Segnan N, Ponti A. Who has Pap tests? Variables associated with the use of Pap tests in absence of screening programmes. Int J Epidemiol 1991;20:349-53
22. Rakowski W, Rimer BK, Bryant SA. Integrating behavior and intention regarding mammography by respondents in the 1990 national health interview survey of health promotion and disease prevention. Pub Health Reports 1993;108:605-24
23. Hyman RB, Greewald ES, Hacker S. Smoking, dietary, and breast and cervical cancer screening knowledge and screening practices of employees in an urban medical center. J Cancer Educ 1995;10:82-87
24. Pearlman DN, Rakowski W, Ehrich B. Mammography, clinical breast exam and Pap testing: correlates of combined screening. Am J Prev Med 1996;12:52-64
25. Orleans CT, Rimer BK, Cristinzio S, Keintz MK, Fleisher L. A national survey of older smokers: treatment needs of a growing population. Health Psychol 1991;10:343-51.
26. McBride CM, Curry SJ, Taplin S, Anderman C, Grothaus L. Exploring environmental barriers to participation in mammography screening in an HMO. Can Epidemiol Biomarkers Prev 1993;2:559-605
27. Beaulieu MD, Beland F, Roy D, Falardeau M, Herbert G. Factors determining compliance with screening mammography. Can Med Assoc J 1996;154:1335-43
28. Bastian LA, Couchman GM, Rimer BK, McBride CM, Feaganes JR, Siegler IC. Perceptions of menopausal stage and patterns of hormone replacement therapy use. J Women’s Health 1997;6:467-75
29. Personal communication with Lori Bastian.
30. King ES, Rimer BK, Trock B, Balshem A, Engstrom P. How valid are mammography self-reports? Am J Public Health 1990;80:1386-88
31. Degnan D, Harris R, Ranney J, Quade D, Earp JA, Gonzalez J. Measuring the use of mammography: two methods compared. Am J Public Health 1992;82:1386-88
32. PM, Mickey RM, Worden JK. Reliability of self-reported breast screening information in a survey of lower income women. Prev Med 1997;26:287-91