Reducing Cost-Related Medication Nonadherence in Patients With Diabetes

In the United States, it has been estimated that 7.8% of the total population has diabetes. In 2007, the direct medical expenditures for diabetes were about $116 billion and the total direct and indirect costs were $174 billion, according to the CDC.¹

Patients with diabetes often have 2 or more comorbidities, such as hypertension, hyperlipidemia, and obesity. Compelling evidence from well-designed clinical trials has demonstrated that control of blood pressure and blood glucose and cholesterol levels can dramatically reduce diabetes complications.^2-4 This often requires the use of multiple medications: it is common for a patient with diabetes to take 10 or more prescription drugs.

An analysis by Rizza and colleagues⁵ shows that in a scenario where goals of diabetes therapy are achieved, medical cost saving could improve by 20%, or an estimated $325 billion, in 30 years. But despite the availability of a wide variety of glucose-lowering drugs and well-established treatment guidelines, current diabetes care is far from optimal. According to the Third National Health and Nutrition Examination Survey conducted from 1999 to 2002, only 50% of the patients with diabetes achieved a glycosylated hemoglobin A_1c (HbA_1c) goal of 7% or less, and 40% met blood pressure recommendations set by the American Diabetes Association.⁶ Adherence to prescribed medications can be challenging and costly, and problems with self-management of drug therapy can exacerbate the burden of disease.⁷

Medication Nonadherence
Medication nonadherence is a serious public health issue. According to the American Heart Association, 12% of Americans do not fill their prescriptions at all, 12% do not take their medicine after they get their prescription filled, 29% stop taking their medicine before it runs out, and 22% take less of their medication than is prescribed. In other words, only 25% of patients are taking their medication as prescribed.⁸

The rate of medication adherence is typically low in patients with chronic conditions, especially in patients with type 2 diabetes mellitus. A review of the literature by Cramer⁹ showed that patient adherence to treatment with oral hypoglycemic agents ranged from 36% to 93% and adherence to insulin therapy was 62% to 64%.

Consequences of nonadherence. Medication nonadherence accounts for more than 10% of all hospitalizations and 23% of all nursing home admissions each year.⁸ It is estimated that medication nonadherence costs the health care system approximately $100 billion a year.¹⁰

Ho and colleagues¹¹ conducted a retrospective cohort study of 11,532 patients in the Kaiser Permanente of Colorado diabetes registry and found that the prevalence of medication nonadherence was 21.3%. Compared with adherent patients, nonadherent patients had higher systolic and diastolic blood pressure and HbA_1c and low-density lipoprotein cholesterol levels. They also had higher rates of all-cause hospitalization and mortality.

A recently published systematic literature review by Salas and colleagues¹² reported that low medication possession ratios in patients with diabetes mellitus were associated with higher health care costs. This review found that there were significant differences in the reported cost of medication nonadherence in patients with diabetes because of various methods used in estimating costs among studies. Some studies have shown that the cost of medication nonadherence in these patients can be up to $11,000 per year per patient.^12,13

Factors affecting medication adherence. According to the World Health Organization, medication adherence is related to social and economic factors, the health care team and system, the characteristics of the disease, therapy-related factors, and patient-related factors.¹⁴ Solving the problems related to each of these factors is necessary in order to improve medication adherence.

Research on adherence has typically focused on barriers such as complex treatment regimens, frequent medication dosing, forgetfulness, adverse drug effects, lack of information, and depression. Financial barriers to medication adherence have not been addressed until recently. In a survey of Americans aged 50 and older, 25% said that they did not fill a prescription written by their doctor in the past 2 years. Cost was cited as the primary reason (40%). Some respondents wished to avoid drug adverse effects (11%); others responded that the drug would not help much (11%), they did not think they needed it (8%), and the drug did not help (6%).¹⁵

Medication Affordability
The number of nonelderly Americans who could not afford their prescription drugs grew from 24.4 million in 2003 to 36 million in 2007, according to the Center for Studying Health System Change.¹⁶

As the recession continues and the unemployment rate grows, the ranks of the uninsured are increasing. Recent data from the Census Bureau showed that the number of uninsured Americans has risen to 46.3 million in 2008-15.4% of the US population.¹⁷

The proportion of patients with employer-provided health care coverage who reported cost-related medication problems increased from 8.7% in 2003 to 10.7% in 2007.¹⁶ The underinsured have health insurance prescription coverage but face significant cost sharing that limits their access to needed drug treatment.

Rising prescription drug costs and less generous drug coverage are likely to be contributing to the increase in unmet prescription drug needs among the underinsured. According to the latest National Health Expenditure data from the Center for Medicare & Medicaid Services, more health care dollars are being spent on medications. Growth in prescription drug spending is projected to outpace spending growth in hospital care and doctor/clinical services.¹⁸

A report released by Medco Health Solutions, Inc, found diabetes medications are now the most powerful driver of drug spending growth. A growing diabetes epidemic and introduction of new treatment options could drive diabetes drug costs by 70% within 3 years.¹⁹ With an increase in pharmacy spending, health plans increase cost sharing with enrollees by raising copayments and coinsurance.

Health plans have also created a fourth tier for high-priced drugs, and enrollees pay a percentage of the cost of drugs. Goldman and colleagues²⁰ found that a 10% increase in cost sharing would result in a 2% to 6% decrease in prescription drug spending. Higher cost sharing is associated with decreased medication adherence and increased use of medical services in patients who have diabetes.

Cost-Related Medication Nonadherence
When faced with financial hardship, people with significant medication expenses will alter behaviors in attempts to save money. They may let prescriptions go unfilled or skip doses or take smaller doses to make the prescription last longer. In a national survey of 875 older adults with diabetes, 19% reported cutting back on use of their medications because of cost, 11% reported cutting back on their diabetes medications, and 7% reported cutting back on their diabetes medications at least once a month. In order to pay for their medications, 20% reported forgoing food and other essentials, 14% increased credit card debt, and 10% borrowed money from family or friends.²¹

Lack of physician-patient communication. Patients who have problems affording their medications do not always tell their health care providers. In a national survey of 660 older adults with chronic illness, 67% of respondents never told their doctors in advance that they are planning to take less medication or not fill a prescription because of the cost and 35% never discussed the issue of cost at all. Of those who did not talk to their doctors, 66% reported that their doctors did not ask about a patient’s ability to pay for medication, 58% did not think their health care providers could help, and 46% were too embarrassed to discuss this issue.²²

Physicians often do not communicate with patients about drug costs. In a survey of 519 physicians, only one-third reported that they knew how much patients are spending out-of-pocket for prescriptions. The most commonly cited barriers to discussion with patients about out-of-pocket costs are insufficient time, concern over possible patient discomfort, and lack of habit.²³ Another barrier is that physicians are unfamiliar with the cost of medications they commonly prescribe. A survey of physicians found that 68% of respondents underestimated the correct price range for all drugs. They reported that regular access to information on prescription drug costs would help them prescribe more cost-effectively.²⁴

Identifying patients and intervening. Specific factors have been identified that may lead a health care provider to ask patients if they will have difficulty with medication costs. If a patient expresses concerns about medication costs, is a racial or ethnic minority, takes 7 or more prescription medications, or has no prescription coverage, his or her provider may be more likely to inquire about difficulty with paying for treatments.²⁵

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