Using Passive Measures to Improve Patient Medication Adherence

Adherence is a complex behavioral process strongly influenced by environmental factors. Six posters designed to improve medication adherence were displayed in a medical clinic, with each poster displayed for 1 month. These posters were seen by clinic patients but, as passive measures, required no additional time on the part of clinicians. Medication adherence to antidepressant therapy was assessed for two 18-month periods. Days of therapy and median gap (the number of days a patient goes without medication before filling the next prescription) were similar between the periods. Medication possession ratio (MPR) was increased in the intervention period (0.974 vs 0.994 days). During the 6-month period that the adherence posters were displayed, persistence decreased by only 10% (versus 22% for the nonintervention period). Use of passive measures may improve patient medication adherence. In this prospective study, both the MPR and persistence were improved. (Drug Benefit Trends. 2008;20:17-24)

When they are enrolled in clinical trials designed to evaluate drug efficacy, patients often receive extra attention from researchers about the need to closely follow or adhere to the drug therapy regimen in order to provide an accurate assessment of a drug's effects. This added attention is generally missing from routine clinical care settings where higher rates of medication nonadherence may lead to the underperformance of medical therapy effectiveness.

Lack of adherence by patients for whom antidepressant medications are prescribed is common. Hansen and Kessing¹ thoroughly reviewed the issue of patient adherence to antidepressant therapies. They found that many patients with depression do not follow their prescribed treatment regimens, with rates of adherence generally lower than those with other types of therapies. In randomized trials of acute therapy for depression, 20% to 40% of patients discontinue therapy before 6 months. In epidemiological trials, more than 50% of patients stop therapy before 6 months.¹

High rates of medication nonadherence with antidepressant therapies are linked to worse outcomes.² In a study assessing medication adherence in privately insured patients who had received a diagnosis of depression, 51% were adherent for the 16-week acute treatment phase; of these, just 42% remained adherent through 33 weeks of therapy.³

A variety of interventions used to improve adherence in chronic conditions, including depression, have been studied. Examples of interventions include the use of personal trainers,⁴ electronic monitoring,⁵ peer-driven interventions,⁶ and behavioral therapy.⁷ Other studies document the effectiveness of various interventions.^8-10

A common thread of most interventions is the need for clinicians to take additional time with patients. Many clinicians, already practicing under significant time constraints, may not feel that they have any additional time to devote to improving patient adherence. This study used passive measures to improve the rate of medication adherence that required no additional action or time on the part of the clinician.

What Is Adherence?
The term "adherence" connotes an active process on the part of patients and is preferred in place of the older term "compliance," which implies no active participation. The meaning of the term "adherence" has changed over time. In 1979, Haynes¹¹ defined adherence as "the extent to which a person's behavior-taking medication, following a diet, executing lifestyle changes-follows medical advice."

A more recent definition of medication adherence by Balkrishnan¹² highlights the active participation of the patient by including the level of participation achieved in a medication regimen once a patient has agreed to the regimen. Patients' behavioral response to medical recommendations, including medication taking, is a complex process that is strongly influenced by the environments in which patients live, in which health care providers practice, and in which health care systems deliver care.^13,14

The rationale for enhancing adherence is rooted in the premise that patients will get well or stay well if they follow appropriate therapeutic recommendations made by health care providers and health care organizations. This assumes that patients have adequate knowledge, motivation, skills, and resources to follow through with these recommendations. However, this assumption is most likely false.

Poor medication adherence has been known about and described in medical literature for decades. During this time, many educational, motivational, and psychosocial approaches have been described and promulgated. Despite improvements seen in specific patient populations, lack of medication adherence continues to be a major obstacle to maximizing patient health. In a 2003 report, the World Health Organization noted that the rate of adherence to long-term therapy for chronic illnesses in developed countries averages only about 50% and is much worse in developing countries.¹⁵

Magnitude and Implications of Nonadherence
The effectiveness of various preventive measures and treatments for persons with cardiovascular disease, stroke, and/or associated risk factors has been demonstrated. Yet many patients do not follow the advice or therapies recommended by their health care providers. The result is that nonadherence with medical therapies adversely affects patients and society.

One study found a discrepancy rate of 76% between medications prescribed and medications (prescription and nonprescription) actually taken.¹⁶ In another study, as many as 40% of seniors did not adhere to their medication regimens.¹⁷

A review of nearly 600 studies found general nonadherence rates to average 25%, ranging from 12% to 35% depending on the disease.¹⁸ This nonadherence rate was estimated to result in 112 million unnecessary visits to health care providers and $300 billion per year in excess health care spending.¹⁸

Patients may end up in the hospital; 22% of hospitalizations have been attributed to patient nonadherence to medical therapies.¹⁹ In a study of California Medicaid patients, the risk of hospitalization was significantly correlated with the extent of medication nonadherence.²⁰

To further meet its goals for improved risk reduction, secondary prevention, and patient outcomes, the American Heart Association convened an expert panel on adherence. The charge to the panel was to (1) evaluate existing models and research related to adherence, (2) determine whether sufficient data exist to make specific recommendations about adherence, and (3) make recommendations for future research to enhance adherence.

The panel reviewed the literature and concluded that the data are sufficient to support recommendations for improving patient outcomes by addressing issues of adherence. ²¹ In its report, the panel made recommendations not only for patients but also for health care providers and organizations. The problem for practicing clinicians, according to findings of the report, is that they lack additional time to devote to new adherence initiatives.²¹

Results of several recent studies suggest that the extent of adherence during the first month of treatment is a powerful predictor of long-term adherence, and many studies show a decrease in adherence rates over time.^22-24

Some studies have shown improvement in adherence rates over time using various interventions^25-27; however, not all interventions are successful. In one study using telephone interventions, medication adherence did not improve even with regular telephone follow-up by a nurse.²⁸ In our current practice setting, time spent with patients is often limited and there are too few nurses and pharmacists to participate in telephone reminder programs.

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