In the context of medical treatment, the term adherence refers to a patient’s success in following the recommendations of a health care provider for disease prevention and treatment. Nonadherence (also called noncompliance) refers to a patient’s failure to follow these recommendations, such as by not filling a medication prescription or by stopping the medication before being instructed to do so, improperly using a medical device, carrying out prescribed behaviors (e.g., specific exercises) incorrectly, or entirely ignoring medical advice (such as to avoid certain foods, or to engage in disease screening). Nonadherence can be purposeful or not. The term “unintentional nonadherence” is used to describe cases in which patients believe (mistakenly) that they are adhering to what has been prescribed, whereas “intentional nonadherence” is used for cases in which patients choose to disregard treatment recommendations completely or to modify their prescribed regimens.

Across a variety of disease conditions, 25% of patients (on average) do not adhere to prevention and disease management activities (including taking medications, going to medical appointments, obtaining screening, exercising, and/or dieting); for some medical conditions, adherence can be as poor as 50% or less. Adherence is a behavior that is strongly connected to health outcomes. On average, the odds of a good health outcome for patients who are adherent are 2.88 times higher than for nonadherent patients. Nonadherence can take a significant toll not only on patient health outcomes but also on providers and the health care system. At the interpersonal level, the inability to achieve health care goals due to nonadherence can be frustrating for both patients and their providers, and from a societal standpoint, nonadherence produces a significant economic burden (between $290 and $300 billion annually in the United States alone). In addition, the number of medical visits wasted annually in the United States as a result of nonadherence is estimated to be at least 240 million.

According to the World Health Organization, adherence is affected by many factors such as: (1) the health care system including the provider–patient relationship, (2) the patient’s disease type and severity, (3) the type of treatment regimen and its complexity, (4) patient characteristics, and (5) socioeconomic factors. This chapter will focus on the interplay of these factors in understanding the role of the provider–patient relationship and communication quality in effective methods for promoting adherence and chronic disease management among all, including the most vulnerable, patients. These include patients of ethnic minority status, low socioeconomic standing, low education level, and/or low health literacy. Emphasis will be placed on targeting individual patients’ needs to promote adherence through the use of a recently devised heuristic model offered by DiMatteo and colleagues, called the Information–Motivation–Strategy Model^©.

Although the elements of the Information–Motivation–Strategy Model^© (IMS Model) were first introduced in the early 1980s, there was insufficient empirical research on which to build support; now, many large-scale empirical trials and meta-analytic reviews provide evidence for the framework of the model. The primary purpose of the IMS Model is to provide health care providers with a valid and practical rubric for remembering and using three broad elements of care that are essential for improving patient adherence. The three components of the IMS Model are Information, Motivation, and Strategy. They reflect the fact that patients can follow only treatments they have been informed about and which they understand; patients will adhere only to treatments they are motivated to adhere to; and patients only do what they are able to within their resource limitations and available strategies.

Information

The information component emphasizes the importance of the knowledge held by patients about their condition and its treatment, and suggests that this knowledge depends most upon effective provider–patient communication. Patients are unlikely to follow a treatment unless its importance is clear to them and they fully comprehend the care instructions. Unintentional nonadherence commonly stems from failure at this stage in the process of care. Research from hundreds of studies indicates that for many patients, their level of health literacy is low and their ability to understand the health information they receive is inadequate. Therefore, health care providers have a responsibility to communicate effectively with their patients and to inform them thoroughly, as well as to check on how well patients understand the information that they are given. A meta-analysis found that in more than a hundred empirical studies, good physician communication skills were associated with increased patient adherence. To encourage patient adherence, health care providers should focus considerable attention on communicating information effectively and on determining patients’ degree of understanding of the treatment regimen. When interacting with vulnerable patients, adequate communication is especially challenging because low health literacy, language barriers, and low levels of education can hinder patients’ full and accurate understanding of what they must do to care for themselves. Health professionals need to identify any specific barriers to communication and attempt to build patient trust in the therapeutic relationship, promote shared decision making, listen to patients, and allow patients to offer essential information on how they plan to follow through with their medical recommendations (see Chapter 18)(Figure 20-1).

Motivation