Drawing from a nationally representative sample of women aged 50 to 74, the present study revealed that food security status had a substantial effect on subsequent breast cancer screening. Respondents who experienced food insecurity were significantly less likely to report engaging in formal breast cancer screening activities (i.e., mammogram or breast x-ray) within the past two years than their food-secure counterparts. This conclusion was drawn after proper adjustments for confounding and selection bias through a PS weighting method utilized to create a balance between food security status subgroups based on a set of observed respondent characteristics, and through redesigning the study to resemble a randomized controlled trial in the best practical way.
The present findings align with the existing research suggesting that food insecurity negatively impacts health services access and utilization among US residents. The existing literature suggests that food insecurity is associated with delaying medical care [37], lower treatment adherence [38, 39], and poor chronic disease management [18, 40]. Berkowitz and colleagues in 2014 attributed these trends to the ‘treat or eat’ dilemma experienced by food-insecure people; in such instances, they are forced to choose between accessing medical services or meeting the basic needs of food and shelter [41]. Our results indicate that women who experience food insecurity may encounter a similar dilemma when considering whether to engage in breast cancer screening. Previous findings have led to a recent call for cancer care providers to integrate food insecurity screening and resources into cancer care [42]. The present study results suggest that addressing the relationship between food insecurity and cancer prevalence must also involve efforts to promote screening behaviors among those who are food-insecure, especially older women at risk for breast cancer.
Among food-insecure women, barriers to breast cancer screening are structural, multilayered, and multi-factorial. Any accumulation, or a combination, of factors addressed in our study, in addition to other unmeasured factors, might partially explain the lower screening rates among food-insecure women. For example, racial and ethnic minority women, those with low socioeconomic status, lower levels of education, and women with comorbid health conditions and disabilities are more likely to be food-insecure, and they are more likely to face logistical, psychological, and cultural barriers to breast cancer screening [11, 14]. Furthermore, among these groups of women, other factors such as lack of health literacy and awareness about breast cancer screening, lack of physician recommendation, concerns about screening success and efficacy, lack of public or private health insurance, and mistrust in healthcare services have been frequently reported to influence their decision to perform or to utilize, breast cancer mammography [1, 11, 14]. Other significant barriers of screening for food-insecure women might include the location of residence and travel times to mammogram centers [12]. In manners similar to ‘treat or eat’ dilemma, food-insecure women could be forced to decide whether to use money and other resources on food, medical care, utilities, or housing [43, 44]. This is more evident for minority women and low-income urban residents who do not have their own transportation and are more likely to depend on public transportation [43]. These facts support the notion that understanding lower breast cancer screening rates among food-insecure women cannot merely be analyzed through their socioeconomic status. Among these women, understanding the full scope of breast cancer screening barriers requires analyses that account for potential barriers at the individual, family, community, policy, and health system levels.
The crude associations between reported breast cancer screenings and respondents’ predisposing, enabling, and need characteristics demonstrated that such screenings were more prevalent among the socioeconomically advantaged––i.e., those with more education, higher incomes, and consistent healthcare access. These findings are consistent with past research suggesting that medical screenings, increased health literacy, and greater perceived control over disease prevention are tied to education level [45, 46]. Similarly, those with higher incomes and reliable healthcare services would be less likely to experience financial, institutional, or environmental barriers in paying for and accessing preventative healthcare such as breast cancer screening services [47]. Conversely, those in socioeconomically disadvantaged groups are more likely to experience food insecurity, which can be a barrier to utilizing preventative health services.
Additional factors that were negatively associated with breast cancer screening in the present study––including smoking and health status––may also be tied to respondents’ socioeconomic status. For example, smoking behaviors, which are most prevalent among those with lower incomes and less education [48], are generally less likely to engage in preventative health behaviors [49]. The mediating role of life stressors, which may be more likely to manifest amongst those of lower socioeconomic standing, on cigarette usage and insufficient usage of preventative health services also merits further investigation [50]. Cancer screenings were also less likely among those with physical disabilities and poor mental health status. Existing scholarship suggests that women with disabilities encounter significant barriers to obtain screenings and may be deterred by factors that include unreliable transportation, lack of preparedness of healthcare providers, undermining or silencing of their questions, scarcity of barrier-free clinics, and the additional effort required to obtain such screenings [51]. Likewise, those experiencing depression often experience limited energy and motivation [52], making it difficult to engage in cancer screening behaviors.
Efforts to address food insecurity among vulnerable populations in the US have shown some promise. For instance, the Supplemental Nutrition Assistance Program (SNAP) is one of the primary mechanisms for reducing food insecurity in these vulnerable subgroups. Recent research has linked SNAP with improved health outcomes both in regard to positive self-assessments and by addressing the ‘treat or eat’ compromise through providing beneficiaries the ability to spend money and resources on their health that would have been spent on food. Moreover, among older adults, such as the women in this study, participation in SNAP report a reduced likelihood of admission to nursing homes or hospitals compared to non-participating counterparts [53]. Although an association between SNAP participation and breast cancer screening rates has yet to be examined, reducing food insecurity among older women could increase their likelihood of utilizing preventative health services. Targeting social determinants of health, such as food insecurity, could trigger a protective mechanism that would promote health among the most disadvantaged populations. Regardless of the mechanism through which food insecurity is negatively associated with breast cancer screenings, the presence of this disparity in a vulnerable population (i.e., food-insecure women) warrants special consideration from policymakers and researchers. Currently, elderly adults contribute to a significant amount of the US disease burden. According to the latest data from the Centers for Medicare and Medicaid Services (2014), women accounted for 56% of total personal healthcare spending. Additionally, women aged 65 years and over accounted for more than 58% of healthcare spending for older adults [54]. Hence, failure to address disparities in preventative health service utilization, including breast cancer screenings, for this demographic subgroup could further worsen their health and increase healthcare expenditures.
The results of our study must be interpreted, bearing several limitations in mind. First, a significant portion of data from HRS, and all data from HCNS, specifically the questions on food security and breast cancer screening, are respondent self-reports, which are prone to bias. For example, there might be underreporting or overreporting of some measures due to social desirability. Second, we followed the guidelines provided by the USPTSF to define the age limits of the studied population; thus, the results are only generalizable to women of ages 50 and 74 in the US. Other agencies, such as the American Cancer Society, have slightly different screening guidelines that include younger age groups below age 50 [3]. Their recommendations encourage women with an average risk of breast cancer to undergo regular screening mammography starting at age 45, and those of ages 45 to 54 to conduct screening annually. Based on those guidelines, there is no cap on age to perform mammography for women as long as their overall health is good, and they have a life expectancy of 10 years or longer [3].
Lastly, while PS weighting is a powerful method for causal associations, it does not control for unobserved covariates. The PS weighing results are interpreted under the assumption of no unobserved confounding. Despite this assumption, unmeasured confounding might still be present, and the assumption cannot truly be tested outside of an actual randomized study. Hence, we were primarily limited to the information provided in the HRS and HCNS surveys. Those unmeasured covariates could have contributed to breast cancer screening differences between the food-secure and food-insecure women.