Drug adherence low for patients new to diabetes therapy

Dr Kirkman

Many studies have shown that nonadherence to medications is associated with numerous adverse outcomes (including hospitalizations, higher costs, and increased mortality).

Now, M. Sue Kirkman, MD, University of North Caroline School of Medicine in Chapel Hill, and colleagues have conducted a retrospective analysis of a pharmacy claims database in order to examine patients’ adherence to diabetes medications.

“We used the medication possession ratio, which is a fairly standard way to assess adherence,” said Dr Kirkman. “We pre-specified a number of variables related to patient factors, provider factors, and prescription factors, and looked at their association with adherence. We then did a multivariate model to look at the independent effects of each variable, since many of them are correlated with one another.”

The researchers found that overall, approximately 70% of patients with diabetes were adherent to their medications.

“Nonadherence was associated with a number of factors, including younger age, being female, being new to diabetes therapy, and being on a few other medications. Nonadherence was also associated with higher out-of-pocket costs and use of retail pharmacies versus mail order,” Dr Kirkman said.

Medication adherence was also independently associated with higher education, higher income, and primary care versus non-endocrinology specialist prescribers, according the study, which was recently published in Diabetes Care.

“We discussed our results primarily in terms of healthcare providers, but I think the findings would be pertinent to managed care and hospital decision-makers in similar ways. Overall, medication nonadherence is fairly common: 30% of patients,” said Dr Kirkman.

There are “nonmodifiable” factors associated with lower adherence (younger age, being female, income level), according to Dr Kirkman, but “we think it’s helpful to be aware of these factors to increase awareness of risks and also to target programs or interventions to improve adherence. There also are potentially modifiable factors that healthcare providers or system leaders could target, such as getting more patients to use mail-order pharmacies or doing more to lower patients’ out-of-pocket costs,” she said.