Medication Adherence Low in Diabetes

Many patients with diabetes may not be adhering to medication regimens and are therefore experiencing higher rates of cardiac events.

In a large cohort of patients with diabetes, rates of adherence for both statins and ACE inhibitors were “alarmingly low” at 34%, with nonadherent patients experiencing a higher rate of major adverse cardiac events (MACE), researchers reported at the American College of Cardiology (ACC) Scientific Sessions 2015.

The study did, however, show that even partial adherence appeared to be associated with a lower cardiac event rate.

“Our findings were very much in line with our hypotheses. I was struck by the fact that only 34% of the high risk diabetic participants were adherent to medications. The fact that more than 80% adherence is associated with a 28% lower risk for major cardiovascular events compared to nonadherence is truly impactful, and a goal I hope clinicians will consider worth striving for,” said study investigator Sameer Bansilal, MD, who is an assistant professor of medicine and cardiology at Mount Sinai Medical Center in New York.

Dr. Bansilal and his colleagues analyzed data on 19,962 patients with diabetes aged older than 55 years who had hypertension or dyslipidemia and had initiated treatment with a statin and ACE inhibitor. They found that 5,645 patients (28%) were nonadherent, 7,571 patients (38%) were partially adherent and 6,746 patients (34%) were fully adherent.

The researchers reported that, compared with the nonadherent group at 2 years of follow-up, the fully adherent group (3.5% vs. 4.6%) and the partially adherent group (3.8% vs. 4.6%), had significantly lower rates of MACE, which was a composite of all-cause death, myocardial infarction, stroke or coronary revascularization.

“Diabetes is as much a cardiovascular disease as an endocrine one. Our endocrinology colleagues will appreciate the troubling issue of polypharmacy and poor medication adherence in their patients. As a physician community interested in improving the outcomes of our diabetic patients, our study drives home the need to employ disruptive and innovative strategies such as emerging technologies, non-physician care models and polypills to get our patients beyond the 80% adherence line to reduce cardiovascular risk,” Dr. Bansilal told Endocrinology Advisor.

He also said evidence-based medications for secondary prevention of cardiovascular disease (CVD) have led to a 50% reduction in mortality in recent years. However, studies linking adherence with outcomes are limited.

In this study, Dr. Bansilal and his team explored the association between levels of medication adherence and long-term MACE in high-risk patients with diabetes. The researchers analyzed a U.S. health insurers’ claims database from 2010 to 2012. They stratified patients as fully adherent (≥80%), partially adherent (≥40% to ≤79%) or nonadherent (<40%).

“I am not surprised at all. Study after study show that in conditions that don’t hurt every day, such as diabetes and hypertension, people think, ‘Why should I take this?’ It might be cost; it might be side effects; it might be a sense of not having control over the disease,” said Kim Eagle, MD, who is a professor of internal medicine and director of the Cardiovascular Center at the University of Michigan Health System in Ann Arbor.

He said this study is very important because noncompliance is such a widespread problem in the treatment of diabetes, and it is very common for patients to say they are taking their prescribed medicines when they are not. Another problem in this area is the difficulty with documenting adherence, according to Dr. Eagle.

“We go over the medications every time we see them. Patients can be passive aggressive and wait until their next visit in 6 months when they have run out of medicine,” Dr. Eagle said in an interview with Endocrinology Advisor. “We need the whole care team — the pharmacists, extended providers and the insurance companies. It is a systems problem. Patients have different availability to caregivers and insurance.”


  1. Bansilal S et al. Abstract 1140-111. Presented at: American College of Cardiology (ACC) 64th Annual Scientific Session & Expo; March 14-16, 2015; San Diego.