To our knowledge, this is one of the first studies4
to examine the associations among financial pressures, cost-related medication non-adherence, and glucose control in a large number of low-income White, Latino, and Asian patients with type 2 diabetes. Previous studies of cost-related medication non-adherence have primarily focused on white23,23
or African American patients.24
The findings from this study suggest that patients who perceived that they had financial burdens related to diabetes were more likely to be non-adherent to medications because of medication cost. Cost-related medication non-adherence was associated with poorly-controlled diabetes, as indicated by higher HbA1c. This relationship persisted, even after controlling for patients’ health insurance status. Having health insurance, however, did mitigate the association between presence of financial barriers to obtaining medical care and patients’ glucose control. This finding suggests that having health insurance may offset some of the financial barriers to obtaining medical care and increase patients’ access to care. Having access to medical care may in-turn be associated with improved glucose control. However, cost-related medication non-adherence remains associated with glucose control, independent of insurance status.
Furthermore, this study found that although both Vietnamese and Mexican-American patients reported having low annual incomes, Mexican-American patients reported having more financial barriers to receiving medical care, more perceived financial burden related to their diabetes, and more cost-related medication non-adherence, compared to Vietnamese and non-Hispanic white patients. While the findings suggest that having health insurance may eliminate some of the financial barriers to medical care that patients encounter, thus potentially accounting for improvements in patients’ access to care, health insurance coverage by itself may not completely mitigate the perceived financial burdens of diabetes faced by low-income Mexican American patients.
This study has several limitations. First, the study was limited to patients living in one region of the country, and may not be generalizable to other geographic areas. Most of the financial variables, except for patients’ insurance status, were based on self-report, and may be subject to social desirability bias. However, social desirability bias would lead to patients under-reporting their financial pressures and medication non-adherence, and would unlikely change the results of the study. Furthermore, there is no indication that one racial/ethnic group would be more susceptible to social desirability bias compared to another group. Recall bias is another limitation that is inherent to self-reported data. However, recall bias should not affect one racial/ethnic group more than another. This study only examined whether patients had different types of health insurance, but did not examine whether patients with health insurance were underinsured (had insurance but had limited coverage). However, we did examine monthly out-of-pocket drug cost, which is one measure of underinsurance. Also, this study did not examine cost-related non-adherence of different types of medications or differences between generic and brand-name medications. These research questions will be the subject for future study. Finally, the study is cross-sectional and thus can only suggest associations and not causality.
This study has several important implications. Medical providers should address patients’ financial pressures during office visits. Patients may be reluctant to bring up their financial situation; however, physicians’ initiation of the conversation may enhance patient satisfaction and trust. Providers who care for low-income patients also should be aware that financial pressures may result in medication non-adherence and poor glucose control, and have candid conversations regarding strategies to reduce medication costs.
On a health system level, it is important to note that increasing health insurance coverage to more Americans may not completely mitigate the financial pressures that diabetic patients face. Health insurance coverage will undoubtedly increase access to medical care and eliminate some of the financial barriers associated with having no health insurance. Many patients, however, especially those who are low-income, may still face significant financial burdens associated with diabetes. Thus, providing health insurance coverage to more individuals is only the first step towards eliminating racial/ethnic health disparities. It is important to find ways to decrease medication cost as a way to improve medication adherence. Decreasing cost-related non-adherence may ultimately result in improved glucose control and possibly decrease diabetes-related mortality.