WOONSOCKET, R.I. — [January 13, 2014] — New research conducted by CVS Caremark (NYSE: CVS) and Brigham and Women’s Hospital published in the January 2014 issue of the American Heart Journal, validates the effectiveness of a widely-used standard for optimal medication adherence. The study confirmed that patients need to achieve a Medication Possession Ratio (MPR) of at least 80 percent — meaning they are adherent to 80 percent or more of their prescription medications – in order to reduce their risk of hospital readmission after a heart attack. Patients with more moderate levels of medication adherence following a heart attack (60-79 percent MPR) derived less clinical benefit from their prescribed medications and had higher levels of disease-related clinical events. An MPR of 80 percent has long been considered optimal, but this threshold had little empirical support.
“These findings underscore the ongoing need for interventions to help patients improve their adherence while confirming the level of optimal adherence needed to see clinical benefit,” said Troyen A. Brennan, MD, MPH, Executive Vice President and Chief Medical Officer of CVS Caremark, and a study co-author. “Interventions could range from identifying ways to remove financial barriers, to determining how best to simplify complicated treatment regimens, to providing tools to help remind and motivate patients about the importance of taking their medications as directed.”
The researchers evaluated the impact of adherence on clinical outcomes for more than 4,100 Myocardial Infarction (MI) patients who had filled a prescription for at least one of the study medications (beta-blocker, statin, angiotensin converting enzyme inhibitor, or angiotensin receptor blocker) prescribed after hospital discharge. The study measured outcomes based on a patient’s first hospital re-admission for a major vascular event (fatal or non-fatal acute MI, unstable angina, stroke, congestive heart failure) or coronary revascularization (coronary bypass, stenting or angioplasty).
The study found patients who achieved adherence equal to or greater than 80 percent MPR to each of the study medications were significantly less likely than the control group to experience a major vascular event or undergo revascularization. For example, patients with optimal adherence of 80 percent MPR or greater 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 (60-79 percent MPR) had no significant reduction in clinical outcomes compared with the control group, despite achieving greater levels of medication adherence.
“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,” said Niteesh Choudhry, MD, PhD, associate physician, Division of Pharmacoepidemiology and Pharmacoeconomics, Brigham and Women's Hospital and associate professor, Harvard Medical School and the lead author of the study.
“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. The data also highlights that it is important for patients who have had a heart attack to reach optimal adherence for all of their recommended medications in order to derive maximal clinical benefit,” Choudhry added.
The study, entitled “Untangling the Relationship Between Medication Adherence and Post-Myocardial Infarction Outcomes,” was based on a secondary analysis of data from the randomized MI FREEE (Free Rx Event and Economic Evaluation) trial conducted by Aetna and Brigham and Women’s Hospital (full results of which were previously published in the New England Journal of Medicine in 2011).
CVS Caremark is focused on developing programs to help improve medication adherence. The study described here helps improve the industry’s overall understanding of medication adherence and enables CVS Caremark to develop more targeted, measureable programs to address the underlying behaviors that contribute to nonadherence. CVS Caremark plans to use these research results along with other key information to identify, develop and pilot breakthrough interventions that will help improve medication adherence for the patients we support. The company is currently evaluating and piloting a number of interventions that range from the development of models to predict a patient’s adherence behaviors in order to better target interventions; to the use of medication reminder devices to help combat forgetfulness; to digital interventions that engage patients to encourage adherence.
CVS Caremark has been working in a multi-year collaboration with Brigham and Women's Hospital to research pharmacy claims data in order to better understand patient behavior, particularly around medication adherence. Annual excess health care costs due to medication non-adherence in the U.S. have been estimated to be as much as $290 billion.