Nearly one-third of Medicare patients do not adhere to medications following MI

A retrospective analysis found that nearly one-third of Medicare patients who were discharged after an acute MI did not adhere to medications within 90 days of leaving the hospital. The medication adherence rates decline within a year of discharge.

Patients who had follow-up visits within six weeks of discharge had significantly better medication adherence.

Lead researcher Kamil F. Faridi, MD, of Johns Hopkins Hospital in Baltimore, and colleagues published their results online in JAMA Cardiology on March 23.

“The data show that adherence to evidence-based therapies among patients after [acute MI] remains low and suggest that greater focus on medication adherence is needed to improve patient outcomes,” the researchers wrote. “Scheduling follow-up within 6 weeks of hospital discharge, especially with a cardiologist, may also be a strategy to help improve medication adherence.”

The researchers examined 20,976 patients who were discharged following an acute MI from 461 U.S. hospitals and were part of the Acute Coronary Treatment and Intervention Outcomes Network Registry–Get With the Guidelines (ACTION Registry–GWTG), a quality improvement registry. ACTION Registry-GWTG includes patients with a primary diagnosis of ST-segment elevation MI or non-ST-segment elevation MI.

The patients in this study were discharged between Jan. 2, 2007, and Oct. 1, 2010, and were enrolled in Medicare Part D at least 90 days before discharge. The mean age was 75.8 years old, and 49.5 percent of patients were men.

The researchers used Medicare Part D prescription filling data and assessed adherence to the following guideline-recommended therapies: beta-blockers, statins, platelet P2Y12 receptor inhibitors and ACE inhibitors or ARBs.

They defined medication adherence as the proportion of days covered of at least 80 percent for each medication.

The median time to the first outpatient follow-up visit was 14 days. Of the patients, 26.4 percent had their first follow-up visit with the first week after discharge, 25 percent had their first follow-up visit between one and two weeks after discharge, 32.6 percent had their first follow-up visit between two and six weeks after discharge and 16 percent did not have a follow-up visit within six weeks of discharge.

Of the follow-up visits, 47.7 percent were with a cardiologist. Patients who had longer times to their first follow-up visit were more likely to be men, black and live in communities with lower median household income, lower median home value and lower rates of high school and college educational levels. They were also less likely to have undergone PCI and more likely to have undergone CABG during their hospitalization for acute MI.

The 90-day and one-year adherence rates were 68.7 percent and 61.1 percent, respectively, for beta-blockers; 63.8 percent and 54.4 percent for ACE inhibitors or ARBs; 63.4 percent and 55.8 percent for statins; and 64.2 percent and 63.5 percent for platelet P2Y12 receptor inhibitors.

The adherence rates were not significantly different between patients with follow-up visits within one week, one to two weeks and two to six weeks. However, patients with follow-up more than six weeks after discharge had lower adherence at 90 days and one year.

The study had a few limitations, according to the researchers, including that it could not determine whether late follow-up contributed directly to lower medication use. They also mentioned they could not distinguish between appropriate medication discontinuation and nonadherence. In addition, they mentioned they measured adherence based on prescriptions filled, so they could not determine if patients used the medications.

The researchers added that patients who do not have a follow-up visit within six weeks of discharge might benefit if they are involved with transitions of care and receive care that involves primary care physicians and cardiologists.

“Because patients with lower socioeconomic status seem to be at higher risk for delayed follow-up and low medication adherence after an [acute MI], increased attention should be placed on this group before and after hospital discharge,” they wrote.