Study Shows Mail Service Pharmacy Improves Adherence for Oral Anti-Diabetic Medications among Medicare Part D Beneficiaries

August 11, 2011

Findings from a new study published online in the Journal of Medical Economics suggest that adherence to oral anti-diabetic medications is improved for Medicare Part D* beneficiaries who receive their medication via mail service.

The study revealed that patients using mail order pharmacy had statistically better adherence (that is, staying on therapy as directed by a physician) than those using retail pharmacies -- 49.7 percent versus 42.8 percent.

“This is the first study to show that mail service can help Medicare Part D members achieve better adherence with their diabetes medications,” said Jacqueline Kosecoff, Ph.D., OptumRx CEO. “Improving adherence has been shown to prevent the worsening of disease outcomes, decrease the use of health resources and control escalating health care costs.”

This study is the first that has examined the impact of mail order pharmacy use on medication adherence among Medicare Part D beneficiaries. The purpose of the study, conducted by Prescription Solutions by OptumRx, was to examine medication adherence specifically among Medicare Part D beneficiaries with diabetes, and to explore whether there is any association between using a mail order pharmacy and better adherence in this patient population. Prescription Solutions by OptumRx is the largest pharmacy benefits manager (PBM) for Medicare Part D.

“Medication adherence is a multi-faceted problem that requires a multi-faceted approach,” said Brian K. Solow, M.D., OptumRx chief medical officer. “Our study provides convincing evidence that mail-order pharmacy would be one way to help improve adherence for patients with chronic diseases.”

While the study suggests further research is needed to understand the causal relationship between mail order pharmacy use and adherence, some aspects of mail service that can be generally associated with better adherence include a high level of safety and affordability to members, automatic refill reminders and the availability of pharmacists 24/7 when customers have a question or concern.

In the study, adherence with oral anti-diabetic medications, such as metformin, sulfonylureas and thioglitazones, was measured by “proportion of days covered” (PDC) during calendar year 2009. Among the overall study population of 22,546 patients with diabetes, good adherence (defined as a PDC greater than or equal to 0.8) was attained by only 41.6 percent of the study population; the average PDC was 0.60. The non-adherence rate (58.4 percent) was higher than what was reported in a previous study (35.1 percent) in the Medicare population§.

However, when compared to retail pharmacy users, mail order pharmacy users demonstrated a significantly higher adherence (0.68 vs. 0.57; P< 0.001) throughout the benefit year. More patients in the mail order group also attained good adherence with their oral anti-diabetic medications (49.7 percent vs. 42.8 percent; P< 0.001).

According to 2011 statistics from the National Diabetes Information Clearinghouse, nearly 11 million adults age 65 and over, or about 27 percent, have diagnosed or undiagnosed diabetes.

Study Population
The retrospective cohort study used electronic pharmacy claims data from Prescription Solutions, which today serves nearly seven million Medicare Part D beneficiaries. The study was reviewed by an external institutional review board.

A total of 22,546 patients were identified, and the majority of them (89 percent) were 65 years or older. Most of the patients (about 78 percent) were enrolled in a stand-alone prescription drug plan. Patients were excluded from the study if they: used insulin or exenatide (brand name, Byetta) during the study period; were low-income subsidies (LIS) recipients; or were receiving antidepressant or anti-dementia drugs during the study period. Two study groups were defined. The mail order group included patients who exclusively used the Prescription Solutions by OptumRx mail-order pharmacies for their oral anti-diabetic medication refills throughout calendar year 2009; the second group included patients who exclusively used retail pharmacies for the same medication refills during the same time period.

About OptumRx
OptumRx is part of Optum, a leading information and technology-enabled health services company dedicated to making the health system work better for everyone. Prescription Solutions by OptumRx is an innovative pharmacy benefit management organization managing the prescription drug benefits of commercial, Medicare and other governmental health plans, as well as those of employers and unions through a national network of 64,000 community pharmacies and state-of-the-art mail service pharmacies in California and Kansas, both of which have earned the prestigious Verified Internet Pharmacy Practice Sites™ (VIPPS®) accreditation by the National Association of Boards of Pharmacy®. Visit or for more information.

About Optum
Optum is a leading information and technology-enabled health services business dedicated to making the health system work better for everyone. Optum is comprised of three companies – OptumHealth, OptumInsight and OptumRx – representing more than 30,000 employees worldwide who collaborate to deliver intelligent solutions that modernize the health system, improve overall population health and support Sustainable Health Communities. Optum serves the broad health care marketplace, including care providers, plan sponsors, government agencies, life sciences companies and consumers.

* Medicare Part D offers prescription drug coverage through stand-alone prescription drugs plans and Medicare Advantage prescription drug plans.
† Part D refers to Medicare prescription drug coverage, which is obtained either through a Medicare Prescription Drug Plan or a Medicare Advantage Plan. []
‡ PDC is a common measure of adherence and has been used in many retrospective studies based on pharmacy claims data. PDC was recently endorsed by the National Quality Forum as an indicator of quality in drug therapy management.
§ Yang et al. Predictors of medication non-adherence among patients with diabetes on Medicare Part D programs: a retrospective cohort study. Clin Ther 2009; 31:2178-88. 


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