What is the Impact of Nonadherence on Public Health and Health Care?

No matter how serious a medical condition is, there are patients who do not use their medications as prescribed. Nonadherence is found even among those patients with serious conditions. A recent study found that 11 percent of women with breast cancer did not take prescribed oral hormonal therapy. Another study determined that only about 20 percent of patients with rheumatoid arthritis used disease-modifying antirheumatic drugs correctly.

In a previous article, we discussed the international prevalence of nonadherence, to give a picture of the scope of the problem. In this piece, we will look at the impact that nonadherence is having on public health, as well as on national economics.

Let’s start with some of the evidence linking poor medication adherence to morbidity, mortality, other health outcomes, and the use of health resources—choosing cardiovascular drugs as examples. A study of more than 15,000 patients with coronary artery disease found a high rate of medication nonadherence, ranging from 21.6 percent for ACE inhibitors to 26.0 percent for statins to 28.8 percent for beta blockers. The investigation found a 50 percent to 85 percent ncrease in the risk of mortality from nonadherence, and a 10 percent to 40 percent increase in the risk of cardiovascular hospitalizations. In a different study of 557 patients with heart failure, nonadherence to medications was associated with a doubling of the rates of mortality and cardiovascular hospitalizations.

Finally, in a recently published analysis of adherence to cardiovascular therapy that reviewed 44 studies involving almost 2 million patients, those with good statin medication adherence (defined as taking at least 80 percent of medications as directed) reduced their risk of death by 45 percent,  whereas those who stuck to their antihypertensive medication diminished their risk of death by 29 percent. Cardiovascular disease-- fatal or nonfatal coronary heart disease, stroke, or sudden cardiac death-- fell by 15 percent for patients adherent to statins, and by 19 percent for those adherent to antihypertensive medications. The study concluded that “a considerable proportion” of all cardiovascular disease events (about 9 percent in Europe) could be attributed to poor adherence to vascular medications. 

Similar trends were found among diabetics who did not adhere to their medication. Diabetic patients who did not take prescribed medications had higher glycosylated hemoglobin, systolic and diastolic blood pressure, and LDL cholesterol levels. Medication nonadherence was associated with increased risks for hospitalization and mortality.

Overall, some serious complications that have been associated with nonadherence include heart attacks in patients with hypercholesterolemia or hypertension; stroke among diabetics; fractures in those with osteoporosis; and major depressive episodes in patients with depression.

Unfortunately, poor public health has consequences even for the healthiest among us.

A 2013 study by the IMS Institute for Healthcare Informatics found “avoidable costs of more than $200 billion are incurred each year in the US healthcare system as a result of medicines’ not being used responsibly by patients and health care professionals. This represents 8 percent of the country’s total annual health care expenditures and amounts to millions of avoidable hospital admissions, outpatient treatments, pharmaceutical prescriptions, and emergency room visits for patients.”  The report said that as the use of medications expanded in the future due to wider insurance coverage, increased incidence and prevalence of chronic disease, and aging of the population, there will be even more need to ensure that medications are taken as directed.

The $200 billion excess cost figure includes nonadherence, delays in providing medications, misuse of antibiotics, medication errors, suboptimal use of generics, and mismanaged polypharmacy. Of all these factors, nonadherence represents the largest avoidable cost, accounting for $105 billion. That figure includes $44 billion for medications associated with high choleserol, $24.6 billion for HIV, and $18.6 billion for high blood pressure.

While three-quarters of the avoidable costs occurred in the hospital, a 2011 study exploring the economics of nonadherence found its impact reaches deep into the pockets of patients. Savings of $8,881 each were found for those adherent patients with congestive heart failure (CHF); $4,337 for high blood pressure; $4,413 for diabetes; and $1,860 for cholesterol problems. Although adherent patients had higher pharmacy spending costs, this group had significantly lower overall health care costs. Excluding those with CHF, savings were even greater for adherent patients 65 years and older.

With the benefits of adherence so clear and the costs of nonadhearence so dear, why is the problem so pervasive? In our next article in this series, we will look at why patients don’t take their medications as prescribed. The reasons might just surprise you.

Thought Leadership