More than a quarter of Medicare Part D beneficiaries were nonadherent to their blood pressure lowering medications in 2014, according to an analysis from the Centers for Disease Control and Prevention (CDC).

The report, which was released Sept. 13, also mentioned that approximately 70 percent of adults who are 65 or older have hypertension. However, the authors noted that only half of patients with high blood pressure have the condition under control.

“A simple action can avoid potentially deadly consequences: Take your blood pressure medicine as prescribed,” CDC director Tom Frieden, MD, MPH, said in a blog post. “Healthcare providers can make treatment easier to help people keep their blood pressure controlled.”

This analysis included 18.5 million adults enrolled in Medicare Part D who filled two or more antihypertensive prescriptions within the same pharmacologic treatment classes on different dates within 90 days. The prescription classes included ACE inhibitors, ARBs, beta blockers, calcium channel blockers, diuretics and other antihypertensives.

The authors defined nonadherence as a proportion of days covered (PDC) of less than 80 percent. They explained that the PDC measures the percentage of days a beneficiary had access to the medication from the time they filled the antihypertensive for the first time until the end of 2014 or the beneficiary’s death in 2014.

They found that 26.3 percent of beneficiaries prescribed antihypertensives were nonadherent to their medications, including 24.3 percent of whites, 26.3 percent of Asian/Pacific Islanders, 33.8 percent of Hispanics, 35.7 percent of blacks and 38.8 percent of American Indians/Alaska natives. In addition, 32.1 percent of patients who received a low-income subsidy were nonadherent compared with 25.4 percent of patients who did not receive a subsidy.

Further, nonadherence was higher in older age groups, among patients who received two or more classes of antihypertensives and among patients who had worse health status. The nonadherence rates based on medication class ranged from 16.9 percent for ARBs to 28.9 percent for diuretics.

Beneficiaries in North Dakota (18.7 percent), Wisconsin (18.8 percent) and Minnesota (18.9 percent) had the lowest nonadherent rates, while those in Washington, D.C. (33.7 percent), Mississippi (32.8 percent) and Louisiana (31.5 percent) had the highest nonadherent rates.

In 2014, Medicare beneficiaries filled 215.9 million prescriptions for antihypertensives at a total cost of nearly $5.9 billion. Beneficiaries were responsible for $2.1 billion of those costs, according to the report. The authors asses that the per-person out-of-pocket spending for antihypertensives was approximately $92 per year, which was 18.4 percent of beneficiaries’ annual prescription medication spending.