CVS Caremark researchers create measurements to predict med adherence behavior

Patients who do the best job of properly taking their medicine tend to be older, with higher incomes and more education, according to a study published in the September 2013 issue of Medical Care.

Those doing the poorest job of following medication regimens tend to be younger, male, and less likely to have received an initial prescription with more than a 30-day supply of medicine.

Those are some of the conclusions of research done by CVS Caremark and Brigham and Women's Hospital that identifies a new approach to classify patients by long-term medication adherence behavior that may be more accurate than traditional approaches.

"Our findings could help facilitate research on medication adherence and medication effectiveness in a variety of ways," said Niteesh Choudhry, MD, PhD, associate physician, Division of Pharmacoepidemiology and Pharmacoeconomics, Brigham and Women's Hospital and associate professor, Harvard Medical School.

"For example, by using group-based trajectory modeling, we could help identify patients with distinct patterns of adherence so that healthcare professionals could appropriately target interventions,” he said. “In addition, data related to the quantity and timing of medication availability could help improve our understanding of the effects of nonadherence on clinical outcomes."

Researchers studied more than 264,000 statin users over a 15-month period and created measures to account for different adherence behaviors. Patients were categorized into groups based on the measurements.

The six groups were characterized as:

·      Nearly always adherent (23.4%);

·      Having a brief gap in medication use or filled irregularly (11.4%);

·      Slowly declining adherence (11.3%)l

·      Using statins only occasionally (15%);

·      Having a rapid decline in statin use (19.3%); and

·      Having virtually no fills (23.4%).

Researchers also identified characteristics that impact medication adherence. The most-adherent patients were more likely to be a Medicare Part D beneficiary, more likely to live in New England, more likely to be a high school graduate, and less likely to be black.

"CVS Caremark continues to engage in cutting-edge research using novel approaches to analyze data so we can better understand the adherence behaviors and needs of the patients we support," said Troyen A. Brennan, MD, MPH, executive vice president and chief medical officer of CVS Caremark.  "The use of trajectory models could help us more accurately identify patients at risk for medication nonadherence, so we can develop and implement targeted interventions to help them stay on their medications for chronic health conditions."