Poor medication adherence is a common problem with serious health consequences. Studies show that up to 30 percent of prescriptions are never filled, and about 50 percent of medications for chronic diseases are not taken as prescribed. Lack of adherence leads to approximately 125,000 deaths annually and is estimated to cost the U.S. health care system up to $289 billion. Some interventions could improve adherence.

Researchers reviewed published studies to assess the comparative effectiveness of patient, provider, systems, and policy interventions that aim to improve medication adherence for chronic health conditions. The researchers found that reduced out-of-pocket expenses, case management, and patient education with behavioral support all improved medication adherence for more than one condition.

The strongest evidence for improving medication adherence was for self-management of asthma and case management or collaborative care with in-person patient education visits for depression. There was limited evidence as to whether these approaches are broadly applicable, or if they can work to improve adherence over the long-term.

"Interventions to Improve Adherence to Self-administered Medications for Chronic Diseases in the United States: A Systematic Review"

Meera Viswanathan, PhD; Carol E. Golin, MD; Christine D. Jones, MD, MS; Mahima Ashok, PhD; Susan J. Blalock, MPH, PhD; Roberta C.M. Wines, MPH; Emmanuel J.L. Coker-Schwimmer, MPH; David L. Rosen, MD, PhD; Priyanka Sista, BA; and Kathleen N. Lohr, PhD