Methods: We conducted survey weighted descriptive, bivariate, and multivariable regression analyses. All analyses were conducted with alpha less than .05 to denote significance.
Results: A total of 25,958 women aged 40 or older were included in our study. Low English language proficiency was found in 8% of the population, while nearly 13% had low health literacy, and another 7% had both. Not having a mammogram was highest among those with both low English language proficiency and low health literacy. Results of regression analysis show that women with both low English language proficiency and low health literacy were 42% less likely to have a mammogram.
Conclusion: Mammogram screening remains one of the most common methods of preventing breast cancer. Our study shows that targeted health education and preventive care is needed for women who do not speak English and have low health literacy.
Women in the United States have more than one in three lifetime risk of developing cancer at certain points in their lives . Among these cancers, breast cancer has one of the highest incidences among women, primarily because of late detection. Thus, breast cancer is currently the second leading cause of cancer-related death among women in the United States. To note, breast cancer can be treated and the risk of dying is lessened when the mutant cells are detected and removed early on. This can only happen when screening becomes part of women's health programs .
In response to this phenomenon, public health programs have been promoting early detection through mammography as a primary strategy for reducing breast cancer-related mortality in the country . This is primarily because increase in mammogram screening reduces breast cancer mortality considering that the number of women diagnosed with late-stage breast cancer is also reduced . At the other end of the spectrum, studies show that women diagnosed with late-stage breast cancer are less likely to have had mammograms prior to their diagnosis in comparison with women diagnosed with early-stage cancer , thus demonstrating the importance of preventive screening.
One of the most pressing barriers to mammograms is poor health literacy. Here, health literacy is defined as "the ability to obtain, process, and understand basic health information and services to make appropriate health decisions". Low health literacy has been linked with a weak health vocabulary that limits how individuals understand key concepts, such as, screening and its benefits. Evidence exists that women with low literacy are more likely to have negative attitudes towards, and negative perceptions of, mammography . Hence, it is common for such women to hold the misconception about mammograms being embarrassing, harmful, painful, and troublesome. A person with limited health literacy tends to not fully understand oral and written information regarding breast cancer screening recommendations and processes.
There are also written materials regarding the significance of early cancer screening which requires 10th to 11th grade reading level so that they are clearly understood . As such, poor literacy makes it difficult for an individual to navigate through the fragmented health care system of the United States, fill up health forms, understand appointment slips, comprehend medication instructions accurately, and communicate effectively with their physician . In light of these, limited health literacy and low English literacy can serve as barriers to the use of mammogram as prevention for breast cancer. As such, there is an imperative need to address if such low health literacy and language proficiency can lower mammogram screening and by utilizing a population-based survey; our study can be generalized to the larger population due to increased external validity.
We utilized the public access adult portion of the 2007 California Health Interview Survey (CHIS). CHIS, considered the largest state health survey, uses random-digit-dial sample to assess the health and behaviors of Californians and the survey is offered in several languages. The primary exposure variable in our study was low health literacy and/or low English language proficiency (LEP): "When you get written information at a doctor's office, would you say that it is very easy, somewhat easy, somewhat difficult, or very difficult to understand?" and "When you read the instructions on a prescription bottle, would you say that it is very easy, somewhat easy, somewhat difficult, or very difficult to understand?" Those responding as "somewhat difficult" or "very difficult" to at least one of these, as well as any participants responding "yes" to the question "The last time you saw a doctor, did you have a hard time understanding the doctor?" were termed low health literacy in our study.
Our primary outcome variable was having mammogram, defined as response of "yes" to ever having a mammogram. The question was only asked to those aged 30 or older, while in our study we primarily focused on those aged 40 or older, as often when such a screening is recommended. Control variables were included: marital status, race/ethnicity, education, poverty, insurance status, and general health status.
Table 1 provides the prevalence of mammogram screening, by each population characteristics. Results highlight that higher prevalence of not having a mammogram was present among those with both LEP and low health literacy (37.94%), followed by those with LEP (28.47%), and those with low health literacy (23.59%), with the lowest prevalence of not having a mammogram being present among those with adequate health literacy and English language proficiency (20.58%).
Table 2 displays the results of survey-weighted multivariable regression analysis. We noted that women with both LEP and low health literacy had 43% lower odds of having a mammogram, as compared to those with adequate health literacy and English language proficiency. In addition, Asian/Pacific Islander women also had lower odds of mammogram (adjusted odds ratio [aOR] = 0.74), compared to White, with similar trend noted for those lacking health insurance in the past 12 months (aOR = 0.69).
The findings establish significance and demonstrate a prevalence of LEP, low health literacy, or both LEP and low health literacy and how such a factor is associated with lower preventive care utilization. The findings echo results such as in a recent study, where Komenaka, et al.  concluded of all the sociodemographic variables examined, health literacy had a strong relationship with use of screening mammography. Based on these findings, it is reasonable to express the continued concerns and need to improve health literacy aimed at healthy outcomes for a vulnerable population, especially those with LEP and/ or low health literacy. While it is encouraging that a large amount of women participated in the research; however, these findings did not come as a surprise since there is a considerable amount of attention in the news media regarding breast cancer awareness . As shown in our results, a key area of needed public health efforts is also the Asian/Pacific Islander population. Due to the model minority myth, often this population is overlooked for health education programs, but our results show that targeted interventions are needed in this population to improve preventive care utilizations. The results, however, should be taken in the context of some limitations. The cross-sectional nature of the study limits causality. In addition, the survey responses are susceptible to recall bias and self-reporting bias. Nonetheless, CHIS is survey-weighted and thus generalizable to the larger California population. In addition, the survey questions have been used previously in the literature and thus holds validation [9,10]. Furthermore, results emphasize the need for further research and must focus on increasing the comprehension of mammography in women with low health literacy and those who do not speak English well. Approaches to increase health literacy can lead to an increase in mammography adherence. Simplifying health literacy can improve health education and have the potential of improving women's health while addressing the existing health disparities and aid in a better understanding of this quandary can help in the strategy of a suitable means to improve comprehension of the appropriate literacy.
2. Davis TC, Rademaker A, Bennett CL, et al. Improving mammography screening among the medically underserved. J Gen Intern Med. 2014;29(4):628-635.
3. Stoll CR, Roberts S, Cheng MR, Crayton EV, Jackson S, Politi MC. Barriers to mammography among inadequately screened women. Health Educ Behav. 2015;42(1):8-15.
4. Pagan JA, Brown CJ, Asch DA, Armstrong K, Bastida E, Guerra C. Health literacy and breast cancer screening among Mexican American women in South Texas. J Cancer Educ. 2012;27(1):132-137.
5. U.S. Department of Health and Human Services, Office of Disease Prevention and Health Promotion. National Action Plan to Improve Health Literacy. Washington, DC. 2010.
6. Egbert N, Nanna K. Health Literacy: Challenges and Strategies. OJIN. 2009;14(3).
7. Komenaka IK, Nodora JN, Hsu CH, et al. Association of health literacy with adherence to screening mammography guidelines. Obstet Gynecol. 2015;125(4):852-859.
8. Quinn EM, Corrigan MA, McHugh SM, et al. Who's talking about breast cancer? Analysis of daily breast cancer posts on the internet. Breast. 2013;22(1):24-27.
10. Tetine Sentell, Kathryn Braun. Low Health Literacy, Limited English Proficiency, and Health Status in Asians, Latinos, and Other Racial/Ethnic Groups in California. J Health Commun. 2012;17(Suppl 3):82-99.