This study suggests that patient barriers are more important than physician barriers for decreased rates of Pap smears and mammograms in obese women, particularly severely obese women. Since physician recommendation is the strongest predictor of cancer screening in women, it is reassuring that physicians are as likely to recommend mammograms and Pap smears to obese as well as non-obese women. The lower prevalence of breast and cervical cancer screening in severely obese women is not due to lack of physician recommendations, but rather to lower adherence to physician recommendations.
Despite the success of the CDC's Breast and Cervical Cancer Early Detection Program in increasing screening in poor and minority women,38
screening disparities still exist for another high-risk group: severely obese women. The reasons for this are unclear. Cancer screening may be a low priority for an obese woman in the context of other personal and family health priorities. 39
Obese women have greater economic and health burdens due to higher poverty, greater number of comorbid conditions, and greater need for physician visits. 40, 41
However, after adjustment for income, comorbidity, and number of physician visits, associations between BMI, screening, and adherence to physician recommendations did not alter. Obese women have greater number of physician visits so they should have more opportunities for cancer screening. Instead, this study shows that despite obese patients having more visits to the physician, they were less likely to have mammograms and Pap smears. Obese persons have more contacts with primary care physicians and see physicians more frequently, presumably to manage chronic conditions, but they might postpone preventive exams that do not address specific symptoms or present illnesses.
Another cause for disparities in cancer screening in obese women may be patient and clinician attitudes. Increasing weight has been associated with having negative opinions about one's appearance and reluctance to obtain pelvic examinations. 29, 42
Obese women may have higher anxiety regarding physical privacy, embarrassment regarding weight, and perceptions of increased pain and discomfort from the procedures.43-45
In addition, obese women may delay preventive exams because they encounter negative attitudes or judgmental behavior from health professionals, they do not want to be weighed, or they do not want to receive lectures regarding weight.42, 46-48
Improving patient-physician relationships and interactions are needed to overcome these barriers.
There appears to be a “threshold effect” in the association of BMI with being up-to-date on mammography and adherence to physician recommendation for mammography. Only the most severely obese women had decreased odds of being up-to-date and adhering to physician recommendations for mammograms, while women in all obese categories were less likely to be up-to-date in CBE and adherent to recommendations for Pap smear. Clinical breast exams and Pap smears require disrobing in physician offices and being physically examined by physicians, so they may be considered to be more personally invasive and uncomfortable than obtaining a mammogram. Prior experience of pain and discomfort with procedures may dissuade obese women from obtaining cancer screenings. 42
In addition, health care facilities may not be equipped for examining severely obese patients. Small size gowns, exam tables, and small speculums are barriers for obese women in receiving preventive health care.42
Although rates for mammography and Pap smears for normal weight and less obese women are near Healthy People 2010 targets of 70% for mammograms and 90% for Pap smears, 49
rates for severely obese women lag behind (62.3% and 76.9%, respectively). While absolute differences of 9% to 10% in proportion of women receiving screening between severely obese and normal weight women may appear small, these findings are concerning given the increasing epidemic of severe obesity in the US 1, 2
and the higher mortality rates for breast and cervical cancer in obese women.9, 10
To reach Healthy People 2010 objectives of reducing death rates from breast and cervical cancer, and increasing proportions of women receiving mammograms and Pap smears, targeting high-risk severely obese women to increase adherence to physician recommendations is needed.
This study has several limitations. All information were derived from self-report data. Concordance between self-reported data on cancer screening and medical record documentation has been found to be satisfactory for purposes of monitoring national level and trends in usage. 50-53
A woman's recall of physician recommendation may be biased, but it is unlikely that reporting errors would differ across BMI categories. Additionally, patients may be subject to recall bias when reporting weight and height, with obese women overestimating height and underestimating weight more than thinner women.54
This would decrease the ability to detect differences across BMI, so these results may underestimate true associations. Women who were up-to-date on screening were assumed to have received recommendations from their physicians, so women who self-referred for screening may have been misclassified. However, few women get mammograms without a recommendation.55, 56
Self-referral is more common at mobile mammography facilities and in women under age 40.55
This sample population consisted of women over age 40, and only 2.29% (n
=153) reported receiving screening in a mammogram van. Finally, it was not possible to control for all confounders or explanatory factors such as patients' health beliefs or attitudes, physician characteristics, or the nature of patient-physician relationships, which may influence cancer screening and adherence to screening recommendations.
In summary, this study shows physicians are as likely to recommend breast and cervical cancer screening to obese women as to non-obese women, but obese women are less likely to adhere to physician recommendations. Despite the critical role of physician recommendations in increasing cancer screening, interventions focusing solely on increasing physician recommendations of mammography and Pap smears will probably be insufficient for obese women. Qualitative studies are needed to examine specific barriers encountered by obese women to understand their reluctance to adhere to physician recommendations for mammograms and Pap smears. Research is needed on strategies to improve the clinician-patient interaction, how this dialogue can be modified when discussing cancer screening in obese women, and how medical facilities can be enhanced to better accommodate severely obese patients. In addition, follow-up is needed with patients once they are given advice to undergo cancer screening to ensure compliance. Since obese women are more likely to develop and die from breast and cervical cancer, additional strategies are needed to make cancer screening more acceptable for this high-risk group.