High Deductibles Leading to Reduced Medication Adherence Among Patients with Diabetes

A repeated cross-sectional study found that health plans with high deductibles, which require thousands of dollars out-of-pocket and have a known association with delays in treatment, are also associated with medication non-adherence. 

Patients with diabetes are counseled on the importance of maintaining a healthy diet, exercise, and adherence to their medications. Adherence is vital to maintain glycemic control, reduce hospitalizations, and prevent further complications. Patients with diabetes often take multiple medications for other chronic conditions, contributing to decreased adherence. Previous studies have shown that glycemic goals are achieved in less than half of patients despite the proven benefits of therapies, increasing morbidity rates. Patients with lower incomes face cost-related medication non-adherence since prices for anti-diabetic medications, especially insulin, have increased. A previous study showed that the average price for insulin increased faster than oral medications, by approximately 200% between 2002 and 2013. This surge in cost is likely a result of increased treatment intensity. 

High deductible health plans (HDHP) require thousands of dollars out-of-pocket. Not only are these health plans associated with increased costs, but also delays in treatment or care. Unfortunately, there have not been any previous studies analyzing the effect of high deductible health plan enrollment on cost-related medication non-adherence surrounding patients with diabetes.  

A repeated cross-sectional study utilizing the National Health Interview Survey between 2011 to 2018 was conducted to analyze nationally representative data on non-elderly patients with diabetes. The objective was to assess the association between HDHP enrollment and measures of cost-related non-adherence among patients taking anti-diabetic medications, the effect of income level, and the risks of hospitalizations. Patients above 65 and who had a commercial plan or any other insurance such as Medicare and Medicaid were excluded from the study. Baseline characteristics were compared between those enrolled in an HDHP and a traditional commercial plan. In addition, the researchers stratified the study sample by income group to assess the effect of income based on the relationship between HDHP enrollment and cost-related non-adherence. Chi-squared tests were utilized to analyze categorical variables in this study.  

The researchers found that enrollees of HDHP and traditional commercial plans did not differ according to age, sex, family income, marital status, and health status. However, HDHP enrollees were more likely to identify as white (69.7%, p<0.01), have a college education (21.3%, p<0.01), and be employed (83%, p<0.01). HDHP enrollees were also more likely to be unable to afford a prescription medication (13.4%, [95% CI 1.5 to 5.4]) and have cost-related non-adherence to insulin (25.1%, [CI 1.1 to 10.8]). In addition, the proportion of patients having cost-related non-adherence was significantly higher in those with lower incomes, and was likely to have more than one emergency department visit.   

Cost-related non-adherence was more common in patients enrolled in HDHP, especially those who used insulin. The researchers also found that cost-related non-adherence resulted in more emergency department visits. Patients who use HDHP are exposed to higher out-of-pocket costs. Until the patient meets their insurance plan deductible for that year, high medication co-pays will likely result in skipping doses. Cost-related non-adherence was found in low, middle, and high-income groups, showing that high out-of-pocket costs can affect patients regardless of income level. Consequently, medication non-adherence has led to increased hospitalizations and worse glycemic control.  

This study could not directly analyze the impact of medication prices; however, newer anti-diabetic medications and insulin were notably the most expensive. In addition, the researchers were not able to assess the duration of insurance coverage or severity of diabetes diagnosis. The actual differences in deductible levels between plan types and their relation to non-adherence were also not accounted for, and the questions in this survey regarding non-adherence were not related to diabetes. Regardless, this study has several implications for clinicians and patients. First, clinicians should be aware that high co-pays can lead to medication non-adherence, especially when prescribing insulin and newer anti-diabetic medications. Second, to help mitigate increasing prices, policymakers should authorize reforms to ensure generic availability, health savings coupons, and lower prices with pharmaceutical companies. Finally, since HDHPs are linked to more significant cost-related non-adherence in patients with diabetes, enrollment in non-HDHPs could potentially reduce this issue in more expensive medications.  

Practice Pearls:  

• Patients with diabetes often face the issue of rising prices in medications, particularly insulin, making it more challenging to practice adherence. 
• A repeated cross-sectional study found that patients enrolled in high-deductible health plans had greater rates of cost-related non-adherence as opposed to other plan types. 
• It is essential to consider patients’ health insurances and deductibles when prescribing anti-diabetic medications, as well as to offer generic and more affordable medications when available. 

García-Pérez, Luis-Emilio et al. “Adherence to therapies in patients with type 2 diabetes.” Diabetes therapy: research, treatment and education of diabetes and related disorders. 

Hua, Xinyang et al. “Expenditures and Prices of Antihyperglycemic Medications in the United States: 2002-2013.” JAMA.   

Rastas, Charlotte et al. “Association Between High Deductible Health Plans and Cost-Related Non-adherence to Medications Among Americans with Diabetes: an Observational Study.” Journal of general internal medicine.  

Dalia Elabed, PharmD Candidate 2022, University of South Florida Taneja College of Pharmacy  

See more about factors contributing to medication non-adherence.