Health care system-level factors may increase likelihood of medication adherence among seniors

Specific system-level factors controlled by health care systems - including prescriptions with a medication supply greater than 90 days, mail-order pharmacy use, and lower copayments and out-of-pocket maximums - nearly doubled the likelihood that patients adhered to prescribed heart and diabetes medications, according to a new study published in the journal Medical Care.

"This study is the first to look at all four of these system-level factors at once in the senior population," said Julie A. Schmittdiel, PhD, research scientist with the Kaiser Permanente Division of Research and the study's lead author. "When all four of these factors are optimized, it nearly doubled the likelihood that patients adhered to prescribed medications for high blood pressure, high cholesterol, and blood glucose level control."

The study reviewed the electronic medical records and pharmacy data of nearly 130,000 Kaiser Permanente members in Northern California, Northwest, and Colorado regions who had diabetes and were over age 65 in 2010.

The Medicare 5-Star Quality Rating System -- the rating system that Medicare uses to assess the quality of health plans -- defines patients as adherent if they have sufficient medication on hand for 80 percent or more of the days in a year. The study reviewed adherence for three heart medications routinely prescribed to people with type 2 diabetes (hypertension medications, statins, and antihyperglycemics).

The Kaiser Permanente study found that medication adherence was about 90 percent for all three medications when seniors with diabetes were: 1) prescribed a 90-day supply, 2) had copays of $10 or less, 3) had out-of-pocket maximum payments that were $2,000 or less, and 4) used mail-order pharmacy for more than half of the year's refills.

"We found that health plans have a number of strong levers to improve patient medication adherence," Schmittdiel said. "Diabetes patients 65 and older are at greatly increased risk of cardiovascular events, and this information will help us design evidence-based interventions that can prevent these events in patients at high risk."