Oral medications and insulin are cornerstones of diabetes man­agement, but as many as one-third of patients with the disease fail to derive optimal benefit from therapy due to medication non-adherence (MNA). Studies have also linked MNA with higher disease-related, inpatient, and emergency department utilization and costs. Unfortunately, many MNA analyses focusing on cost have been limited by small sample size, an absence of precise adherence measures, or cross-sectional design, among other limitations.

In an issue of Diabetes Care, my colleagues and I published an article designed to overcome previous research limitations and add to our existing knowledge on the effects of MNA on cost. In our study, we used a multivariate, generalized, linear, mixed model in order to account for shared correlations among cost variables. We then estimated the inpatient, outpatient, and pharmacy-related costs in a group of more than 740,000 veterans in the United States with type 2 diabetes over a 5-year period.


Inpatient Costs: A Key Driver

According to our findings, the costs of MNA among patients with diabetes are quite large and appear to be mostly driven by inpatient expenditures. All annual cost categories increased by about 3% per year. MNA was associated with 37% lower pharmacy costs and 7% lower outpatient costs but 41% higher inpatient costs. The potential cost savings that might be achieved from improving medication adherence are substantial. Based on sensitivity analyses, improving adherence for MNA patients would lead to annual estimated cost savings that range between $661 million and $1.16 billion.

Wanted: More Successful Interventions

The findings from our study are significant to both health services researchers and healthcare policy makers. In order to realize potential health benefits and cost savings, successful interventions are needed to improve adherence and self-care behaviors among patients with diabetes. Other studies have suggested that several healthcare policy changes may further improve medication adherence, including:

• Decreased cost sharing for those with pharmacy benefits.

• Expansion of pharmacy benefits to more patients.

• Medication review visits by clinical pharmacists.

Innovative strategies for medication adherence continue to be explored, including individually tailored behavior change interventions, peer health coaching, diabetes self-management website engagement, and technology-assisted case management. Further research is needed to address additional barriers to medication adherence, including regimen complexity, medication beliefs, and treatment of comorbid depression. If successful strategies can be found, such approaches could further our chances of achieving the so-called “triple aim” of achieving better health, better quality care, and lower cost.


Egede LE, Gebregziabher M, Dismuke CE, et al. Medication nonadherence in diabetes longitudinal effects on costs and potential cost savings from improvement. Diabetes Care. 2012;35:2533-2539. Available at: http://care.diabetesjournals.org/content/35/12/2533.long.

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Cramer JA, Pugh MJ. The influence of insulin use on glycemic control: how well do adults follow prescriptions for insulin? Diabetes Care. 2005;28:78-83.

Lynch CP, Strom JL, Egede LE. Disparities in diabetes self-management and quality of care in rural versus urban veterans. J Diabetes Complications. 2011;25:387-392.

Egede LE, Mueller M, Echols CL, Gebregziabher M. Longitudinal differences in glycemic control by race/ethnicity among veterans with type 2 diabetes. Med Care. 2010;48:527-533.