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Health System Factors Improve Medication Adherence Among Seniors with Diabetes

March 16, 2015

Two senior men sitting eating food and drinking coffee outside having a nice time

OAKLAND, Calif. — 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 the 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).

A woman in a warehouse with a cart among rows and rows of shelves containing medicine.

Kaiser Permanente Pharmacy Tech Cassandra Culpepper processes mail-order refills at a Central Refill Pharmancy in Downey, Calif.

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.”

Kaiser Permanente can conduct transformational health research such as this study in part because it has the largest private patient-centered electronic health system in the world. The organization’s electronic health record system, Kaiser Permanente HealthConnect®, securely connects approximately 9.6 million patients to 17,000 physicians in more than 600 medical offices and 38 hospitals. It also connects Kaiser Permanente’s research scientists to one of the most extensive collections of longitudinal medical data available, facilitating studies and important medical discoveries that shape the future of health and care delivery for patients and the medical community.

In addition to Schmittdiel, co-authors of the study were Wendy Dyers, MS, and Andrew J. Karter, PhD, Kaiser Permanente Division of Research, Oakland, California; Gregory A. Nichols, PhD, Kaiser Permanente Center for Health Research, Portland, Oregon; and John F. Steiner, MD, MPH, and Marsha A. Raebel, PharmD, Kaiser Permanente Institute for Health Research, Denver.

The study was funded by the Kaiser Permanente Center for Effectiveness and Safety Research, and the Agency for Healthcare Research and Quality.

About the Kaiser Permanente Division of Research
The Kaiser Permanente Division of Research conducts, publishes and disseminates epidemiologic and health services research to improve the health and medical care of Kaiser Permanente members and society at large. It seeks to understand the determinants of illness and well-being, and to improve the quality and cost-effectiveness of health care. Currently, DOR’s 550-plus staff is working on more than 250 epidemiological and health services research projects. For more information, visit or follow us @KPDOR.

About Kaiser Permanente
Kaiser Permanente is committed to helping shape the future of health care. We are recognized as one of America’s leading health care providers and not-for-profit health plans. Founded in 1945, Kaiser Permanente has a mission to provide high-quality, affordable health care services and to improve the health of our members and the communities we serve. We currently serve approximately 9.6 million members in eight states and the District of Columbia. Care for members and patients is focused on their total health and guided by their personal physicians, specialists and team of caregivers. Our expert and caring medical teams are empowered and supported by industry-leading technology advances and tools for health promotion, disease prevention, state-of-the-art care delivery and world-class chronic disease management. Kaiser Permanente is dedicated to care innovations, clinical research, health education and the support of community health. For more information, go to