Diabetes Nonadherence Greater in Young Adults

Patients with diabetes mellitus (DM) who are younger, new to the disease, and receiving few other medications may be at risk for nonadherence to therapy, according to a new study.

“Medication nonadherence is fairly common, in about 30% of patients. There are ‘non-modifiable’ factors associated with lower adherence, such as younger age, being female, and lower income level. 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,” M. Sue Kirkman, MD, from the University of North Carolina School of Medicine, Chapel Hill, told ConsultantLive.

“There also are potentially modifiable factors that health care providers could target, such as getting more patients to use mail-order pharmacies or doing more to lower patients’ out-of-pocket costs,” she added.

Many prior studies have shown that nonadherence to antidiabetic medications is associated with many adverse outcomes, including hospitalizations, higher costs, and increased mortality.

Dr Kirkman and colleagues conducted a retrospective analysis of a large pharmacy claims database to examine patient, medication, and prescriber factors associated with adherence to antidiabetic medications. They extracted data on a cohort of more than 200,000 patients who were treated for DM with noninsulin medications in the second half of 2010 and had continuous prescription benefits eligibility through 2011. They used the medication possession ratio, a fairly standard way to assess adherence.

“We prespecified a number of variables related to patient factors, provider factors, and prescription factors and looked at their association with adherence,” Dr Kirkman said. “We then did a multivariate model to look at the independent effects of each variable, since many of them are correlated with one another.”

Overall, 69% of patients were adherent. Nonadherence was associated with a number of factors, including younger age, being female, being new to DM therapy, and receiving few other medications. Nonadherence also was associated with higher out-of-pocket costs and use of retail pharmacies vs mail order.

“We speculate that nonadherent patients may not view themselves as ‘ill’ and may be less likely to take medications for an essentially asymptomatic disease, while older patients who have more comorbidities and are more used to taking medications might be more likely to stay on their diabetes medications,” Dr Kirkman said, noting that the researchers did not talk to patients directly.

“This suggests that acceptance of a chronic illness diagnosis and the potential consequences may be an important, but perhaps overlooked, determinant of medication-taking behavior,” she noted.

In conclusion, the researchers suggested that “health care providers should consider many factors beyond common wisdom when addressing the issue of medication adherence. They should not assume that patients who seem uncomplicated (young, with newly diagnosed type 2 diabetes, without substantial comorbidities) are free of barriers to medication adherence. In fact, they may need more support to help them overcome barriers to adherence, one of which may be accepting the reality of having a chronic illness.”

The researchers published their results online January 8, 2015, in Diabetes Care.