Medication Adherence Rates Sink, Renew Calls for Cost and Policy Change

February 03, 2023 - Medication adherence remains a problem for chronic disease management, with new data in JAMA Network Open showing that around one in five adults with diabetes did not maintain use of glucose-lowering medications between 2005 and 2018.

Meanwhile, an average of 17 percent and 43 percent of patients did not consistently take their blood pressure- or lipid-lowering medications during that same period, the researchers added.

Medication adherence is crucial to chronic disease management. Patients who consistently take their medications as prescribed are more likely to experience good outcomes and avoid costly acute care episodes.

That doesn’t just make for better quality of life; medication adherence and good outcomes are also linked to lower healthcare costs. And with healthcare increasingly embracing value-based care, those lower costs are important.

For folks with diabetes in particular, poor medication adherence—which can be blamed on high medication costs in many cases­—can have direct clinical outcomes, the researchers said.

“Suboptimal medication adherence among people with type 2 diabetes has been associated with preventable complications and the onset of serious health problems, such as heart disease, kidney disease, or amputation,” they explained.

That suboptimal medication adherence is coming to fruition, the researchers said. Through an analysis of some 15,000 patients with diabetes, the researchers found that adherence to glucose-, blood pressure-, and lipid-lowering medications is low.

Using information from the Medical Expenditures Panel Survey (MEPS) from the 2005-2006 and 2017-2018 panel years, the researchers found that medication adherence among individuals with diabetes is, in fact, on the decline.

For example, regular use of glucose-lowering medications went down from 84.5 percent in the 2005-2006 panel year to 77.4 percent in the 2017-2018 panel year. By the end of the study period, the researchers found that 7.1 percent of patients had inconsistent use of glucose-lowering drugs, and 12.9 percent did not use the medications at all.

Over the entire study period, an average of 19.5 percent of patients did not use glucose-lowering medications.

A similar trend emerged for use of blood pressure- and lipid-lowering medications. Over the course of the study period, the rate of inconsistent blood pressure-lowering drug use rose from 3.9 percent to 9 percent. For lipid-lower medications, rates rose all the way up to 9.9 percent in the 2017-2018 panel year.

Over the entire study period, an average of 17.1 percent of patients did not use blood pressure-lowering medications and 43.2 percent did not use lipid-lowering medications.

The study did not specifically seek out the factors contributing to suboptimal medication adherence, but the researchers did indicate that affordability and insurance coverage had something to do with it.

While most studies of medication adherence rely on insurance claims data, this study used MEPS data and was able to include medication adherence patterns for individuals without insurance. That likely skewed the data downward, indicating more widespread problems in medication adherence, the researchers noted.

“In our nationally representative data for adults with diabetes, uninsured adults were more likely to use no medications or inconsistently use medications for both years of follow-up, which is consistent with another study that found an association between financial barriers and medication adherence among adults with diabetes,” they said.

This study also found some age-based and racial health disparities at play, with younger people and Black people being less likely to have consistent medication use than their older, White peers. Latino patients were also less likely to consistently use blood pressure- and lipid-lowering medications.

“These differences across minority racial and ethnic populations may reflect heterogenous individual and systemic factors,” the researchers wrote. “In surveys, Latino individuals with diabetes referenced cost barriers to medication adherence.  Alternatively, Black patients referenced worse complications and lack of trust in the health care system and pharmaceutical therapies.”

These findings indicate that more needs to be done to manage medication adherence problems, the researchers said. Although medication adherence can be bolstered by patient-facing tools like mail-order pharmacies and medication management tools, the reality is that cost and other policy-level issues continue to drive poor medication adherence.

“The pharmaceutical industry, payers, clinicians and health systems, and policy makers have introduced interventions to improve medication adherence, such as use of clinician outreach and mail order pharmacies,” the researchers concluded. “However, changes and inconsistencies in payer formularies and out-of-pocket cost burden, especially among adults with no or insufficient insurance (ie, Medicare Part D), remain prominent issues.”