Findings from a recent study indicate that the less U.S. patients pay out of pocket for drugs that often have high co-pays, such as sodium-glucose cotransporter 2 (SGLT2) inhibitors or glucagonlike peptide-1 (GLP-1) agonists, the more they adhere to taking these medications.
The study, led by Utibe R. Essien, MD, from University of California, Los Angeles, and Balvindar Singh, MD, PhD, from University of Pittsburgh, was published online in JAMA Cardiology.
Patient data from Clinformatics Data Mart, a health insurance claims database, was analyzed for the study. The information for 90,041 adults from the United States who had commercial and Medicare health insurance, and who started taking a GLP-1 agonist or SGLT2 inhibitor between 2014 and 2020 was reviewed. Participants had type 2 diabetes, heart failure, or both.
The primary outcome showed patients with a lower drug co-pay had significantly higher odds of 12-month adherence to GLP-1 agonists and SGLT2 inhibitors, compared with those with a higher co-pay. These differences persisted after controlling for patient demographic, clinical, and socioeconomic covariates.
After full adjustments were made and after the 12 months, patients with a high co-pay of $50 per month or more were 53% less likely to adhere to an SGLT2 inhibitor and 32% less likely to adhere to a GLP-1 agonist, compared with patients with a co-pay of less than $10 per month for these agents.
“Lowering high out-of-pocket prescription costs may be key to improving adherence to guideline-recommended therapies and advancing overall quality of care in patients with type 2 diabetes and heart failure,” the authors conclude.
The authors acknowledge the study’s limitations, including the inability to exclude residual confounding, uncertain generalizability for those without health insurance or with public insurance and possible misclassifications of type 2 diabetes and heart failure diagnoses or medical comorbidities. Additionally, this study did not have information on patients’ preferences associated with medication use, including specific reasons for poor adherence, and could not assess how co-payments influenced initial prescription receipt or abandonment at the pharmacy, or other factors including possible price inflation.
The study received no commercial funding. One author (not a lead author) is an adviser to several drug companies including ones that market SGLT2 inhibitors or GLP-1 agonists.