Why Patients Won't Fill Your Prescriptions

Charles P. Vega, MD


September 02, 2014

In This Article

Americans and Their Prescriptions

Americans receive more and more prescriptions for medications, with nearly one half of us being prescribed at least 1 medication in the past month. However, previous research has suggested that a high percentage of these prescriptions are never filled, and a recent prospective cohort study[1] involving over 15,000 patients documented a 31% rate of nonadherence for new medications. Moreover, there are disturbing trends in this research demonstrating a high rate of nonadherence for medications designed to prevent severe medical conditions. The current review highlights these findings and offers an analysis of interventions to improve medication adherence.

America Is on Drugs

The United States is addicted to drugs -- prescription drugs, that is. According to data from the Centers for Disease Control and Prevention examining prescription drug use from 2007 to 2008,[2] 48% of Americans reported receiving at least 1 prescription drug during a single month, a 9% increase since the measurement period of 1999-2000. This same survey found that 31% of patients reported using at least 2 or more prescription drugs during the previous month; 11% of those surveyed were using 5 or more prescription products in the month before their participation in the survey. In adults older than 60 years, these respective rates were 76% and 37%.

Someone has to be prescribing all of these medications. This research demonstrated that having a regular source of medical care increased the rate of prescription drug use nearly threefold. Health insurance featuring a prescription drug benefit was associated with a 22% increase in the rate of using prescription drugs.[2]

The most commonly used prescriptions among individuals between 20 and 59 years of age were antidepressants. Cholesterol-lowering medications, followed by beta-blockers and diuretics, were the most commonly used agents among older adults.[2] All of these data were drawn from validated national surveys, and should reflect the state of affairs for prescription drug use in the United States.

However, for all of the prescriptions written in the United States, it is clear that many are never filled by patients. One study using a pharmacy database demonstrated that the rate of failure to fill a new prescription, termed "primary nonadherence," was 9.8%.[3] Another retrospective large study examining claims data found an overall rate of prescription nonadherence of 22%, with a failure-to-fill rate for new prescriptions of 28%.[4]

As expected, multiple variables affect adherence rates for prescription therapy. In previous research, treatment for chronic disease has been found to be the most consistent variable in higher rates of nonadherence.[3,4] Prescriptions from primary care physicians, particularly pediatricians,[4] and black vs white race[3] have also been significantly associated with medication nonadherence.

Nonetheless, there remains much to be learned regarding the causes of nonadherence to prescription treatment. A greater understanding of associated risk factors can improve patient management outcomes in the era of accountable care. A recent study[1] evaluates these variables from the perspectives of the patient, practitioner, and healthcare system.


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