About one diabetic in three never fills the doctor’s prescription for antidiabetic medication, according to a study based on a new method of capturing a comprehensive picture of pharmaceutical compliance data.

Appearing in the February issue of the Journal of General Internal Medicine, the study is the first to link physician medication orders from Geisinger Health System’s robust electronic health record with insurance claims to show that far more diabetics than previously estimated choose not to fill their prescriptions. The findings point to the importance - in terms of long-term wellness and cost-savings - of engaging patients in their diabetes care.

While previous studies have relied only on insurance claims for estimates of diabetic patients who fill antidiabetic (antihyperglycemic) prescriptions, the Geisinger study is the first to capture actual physician prescription orders as well as prescription insurance claims to link data to patient diagnosis and history.

For the estimated 1.5 million newly diagnosed diabetics in the United States each year, unwillingness to fill antihyperglycemic prescriptions is a costly problem. The estimated 35 percent non -fill rate corresponds to 400,000 new diabetic patients each year. Untreated for early-stage diabetes, many of these patients will become candidates for more costly second-line medications that are more likely to cause adverse side effects.

According to the study’s lead author, Nirav Shah, MD, senior investigator, Geisinger Center for Health Research, the findings provide valuable insight into patient preferences and behaviors that can help healthcare providers as well as pharmaceutical researchers develop treatment regimens that patients are more likely to follow. Specifically, this would involve addressing why patients choose not to fill prescriptions and the significance of pursuing mutually acceptable options.

“Despite the perception that healthcare providers must intensify treatment over time to manage diabetic patients, our study shows the equally important and often underestimated role of engaging patients in their care,” said Dr. Shah.

About the Study
The retrospective cohort study from 2002 to 2006 analyzed 1,132 patients over the age of 18 who sought care from the Geisinger Clinic, had Geisinger Health Plan pharmacy benefits and were prescribed an antihyperglycemic medication. The authors analyzed the prescription fill rates within 30 days of the prescription order date.

The study found that copays less than $10 and baseline A1c greater than 9 percent were associated with improved first-fill rates; gender, age and co-morbidity score appeared to have no association. Not surprisingly, significant reductions in A1c rates were seen in patients who filled their diabetic medication prescriptions, although some decreases in A1c also were seen in non-filling patients, possibly due to increased adherence to diet and exercise guidelines.

In addition, the study found that patients who were prescribed first line diabetics medications such as biguanides and sulfonylureas were more likely to fill their prescriptions compared with patients who were prescribed second line oral agents or insulin.

The study authors suggest that future research should utilize electronic health record data to quantify medication adherence at each interval of the prescription cycle.