Patients with lower levels of medication adherence following a heart attack derived less clinical benefit, according to new research from Brigham and Women’s Hospital and CVS Caremark, published in the January 2014 issue of the American Heart Journal.
The study provides empirical evidence for what has long been used as a benchmark in the drug industry for optimal medication adherence — “Medication Possession Ratio (MPR),” reflects the amount of prescription medicine a patient actually takes.
“This research clearly demonstrates that the long-held industry standard of 80 percent MPR is associated with improved health outcomes and reduced adverse coronary events for post-heart attack patients,” said Niteesh Choudhry, MD, PhD, associate physician at Brigham and Women’s, and lead author of the study.
The data, according to Choudhry, an associate professor at Harvard Medical School, highlights how important it is for patients who have had a heart attack to take their medications as prescribed.
The study further demonstrates the ongoing need for interventions to help patients achieve adherence, said Dr. Troyen A. Brennan, chief medical officer of CVS Caremark, and a co-author of the paper.
“Interventions could range from identifying ways to remove financial barriers, to determining how best to simplify complicated treatment regimens,” Brennan said, “to providing tools to help remind and motivate patients about the importance of taking their medications as directed.”
The study, “Untangling the Relationship Between Medication Adherence and Post-Myocardial Infarction Outcomes,” was based on a secondary analysis of data from a trial conducted by Aetna and Brigham and Women’s Hospital, published in the New England Journal of Medicine in 2011.
The researchers evaluated the impact of adherence on clinical outcomes for more than 4,117 myocardial infarction (MI) patients, and measured outcomes based on a patient’s first hospital readmission for a major vascular event or coronary revascularization.
The study found that patients who achieved adherence equal to or greater than 80 percent were significantly less likely than the control group to experience a major vascular event or undergo revascularization.
For example, the study found that patients with at least 80 percent adherence were 24 percent more likely not to be readmitted to the hospital for another heart-related issue than the control group. In contrast, “partially adherent” patients — who had between 60 percent to 79 percent adherence — had no significant reduction in clinical outcomes.
“While it is widely accepted that patients who are adherent to prescribed medications for chronic conditions have better outcomes than non-adherent patients, there has not been solid data that defines the optimal level of adherence,” Choudhry said.
Nonadherence to prescription drugs leads to poorer health outcomes, increased hospitalizations and costs up to $290 billion annually, according to a report from NEHI. Non-adherence is considered one of the leading causes of excess healthcare costs in the United States.
The research is the result of a partnership between CVS Caremark and Brigham and Women’s Hospital that aims to better understand patient behavior around medication adherence.