Health-System Variables Improve Medication Adherence in Medicare Patients

As the US Centers for Medicare and Medicaid Services (CMS) places a greater emphasis on medication adherence through its star ratings, pharmacists and other health care professionals continue to seek ways to improve adherence among seniors.

Now, a new study published in Medical Care has determined that prescriptions with more days’ supply of medication, mail-order pharmacy fills, and lower co-pays and out-of-pocket maximums are all associated with better adherence to drugs for diabetes and cardiovascular disease (CVD).

After finding a dearth of research on adherence among older patients with diabetes and seniors who take medications for CVD risk factors, researchers sought to examine the relationship between the Medicare 5-Star Quality Rating System’s medication adherence metrics and adjustable health-system-level characteristics among older patients with diabetes.

The study involved 129,040 patients aged ≥65 years taking antihypertensive, antihyperlipidemic, or oral antihyperglycemic medications. The 4 health-system variables that the researchers believed were potentially modifiable were average days’ supply of medications, annual out-of-pocket maximum costs, generic drug co-pays, and the percentage of medications delivered through mail-order pharmacies.

The strongest predictor of reaching star-defined medication adherence was a >90-day supply of prescribed medication. In addition, the use of mail-order pharmacies to fill medications was independently associated with better adherence >50% of the time.

While this relationship has been demonstrated in younger populations, the researchers noted that their study was the first to examine the relationship among Medicare-aged patients with diabetes. In addition, the study showed that black and Hispanic patients especially showed a great adherence benefit from mail-order pharmacies.

Co-pays that were ≤$10 for a 30 days’ supply and annual individual out-of-pocket maximums that were ≤$2000 were also associated with higher adherence.

By optimizing these 4 variables, good medication adherence prediction percentages were shown to nearly double when compared with health-system-level factors that were less optimized, including a <31-day supply of medication, a copay of >$10, out-of-pocket maximums of >$2000, and no mail-order pharmacy fills.

The predicted percentages of patients with the most optimized variables achieved roughly 90% adherence, while those with less optimized variables were predicted to have 50% adherence.

Adherence of roughly 90% exceeds what is necessary to achieve a CMS 5-star rating, the researchers noted.

“This suggests that multifactorial efforts to lower system-level barriers to obtaining medications can profoundly impact health plan Medicare star scores for CVD risk factor medication adherence,” the authors concluded.