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Intersection of Biology and Behavior

Examining Theoretic Models of Adherence for Validity in Resource-Limited Settings

A Heuristic Approach

Ware, Norma C PhD*; Wyatt, Monique A*; Bangsberg, David R MD

Author Information
JAIDS Journal of Acquired Immune Deficiency Syndromes: December 1, 2006 - Volume 43 - Issue - p S18-S22
doi: 10.1097/01.qai.0000248343.13062.4b
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Mortality and morbidity for HIV-infected patients in resource-limited settings have declined markedly with increased access to combination antiretroviral therapy (ART) (Oyugi et al, submitted for publication).1-4 The high rates of adherence that patients being treated with ART in these settings have achieved are one explanation for this.2,3,5-13 In other parts of the world, however, where patients have now been receiving ART for years, adherence has declined over time.14-18

Such declines suggest that the course of adherence begins with a “honeymoon period” in which dramatic health gains fuel strong initial commitments to taking medications as prescribed.19 The honeymoon period ends as patients come to take improved quality of life for granted and the long-term side effects of treatment (eg, neuropathy, lipodystrophy) begin to make themselves felt. The first signs of declining adherence are already beginning to emerge in Africa (Oyugi et al, submitted for publication).11

It is not too early to anticipate the end of the honeymoon period in resource-limited HIV treatment settings. Anticipation means beginning now to think about what is needed to sustain early adherence successes and taking steps to put effective supports into place. Planning for effective long-term adherence supports should grow out of empirically derived detailed understanding of adherence processes in particular locales. This understanding is best arrived at using socioculturally valid theoretic models as a guide.

What are socioculturally valid models of adherence and how can we obtain them? We may consider a model to be socioculturally valid when it accurately and comprehensively represents the dynamics of adherence for a socially and/or culturally defined group. Models developed for use in a specific sociocultural context cannot simply be assumed to be valid in another. They must be validated and, if necessary, adapted to fit the new settings in which they are applied.

In what follows, we lay out a heuristic schema for assessing existing theoretic models of adherence for cross-cultural validity. The schema consists of 4 analytic questions. To apply the schema, each question is asked of a model being considered for use in a sociocultural context other than the one in which it was developed. The questions are as follows:

  1. Are the model's basic concepts relevant in the new setting?
  2. Are basic concepts important to the new setting represented in the model?
  3. Are the meanings of the model's basic concepts accurate for the new setting?
  4. Does the model capture the complexity of adherence in the new setting?

A model's basic concepts (questions 1 and 2) are its key conceptual domains. Meanings (question 3) refer to the ways in which basic concepts are specified. The multiple interrelated influences that combine to shape adherence constitute its complexity (question 4).

An Illustrative Case: Information-Motivation-Behavioral Skills Model of Adherence

To demonstrate use of the schema, we carry out an illustrative validation exercise in which the 4 analytic questions are applied to a well-known theoretic model of behavior change: the information-motivation-behavioral skills (IMB) model.20-23 The IMB model has been used to understand HIV-related health behaviors and to inform the development of preventive interventions.24-28 It is now attracting increasing attention as an approach to the study of adherence.29-31

Grounded in health and social psychology, the IMB model depicts adherence as a health behavior determined principally by an individual's (1) relevant knowledge (information); (2) attitudes toward taking antiretroviral medications (eg, perceived benefits of taking medications, perceptions of social support) (motivation); and (3) ability to perform necessary adherence-related tasks, together with a sense of self-efficacy (behavioral skills). The basic concepts of IMB are construed as having direct and indirect impacts on adherence. Adherence, in turn, is seen as affecting health outcomes, which influence subsequent IMB through a feedback loop. The model also includes a provision for situational and individual characteristics (eg, access to medical care, psychologic health) that may moderate the proposed relations among its components (Fig. 1).

The IMB model of adherence.

Sources of Information for the Illustrative Exercise

Information used to address the 4 analytic questions and complete the illustrative exercise comes from preliminary qualitative research carried out in 2 HIV treatment settings in East and West Africa. The research included interviews with patients and health care practitioners and observations of clinical activities.

The East Africa setting is the HIV/AIDS Clinic at Mbarara University Teaching Hospital (MUTH), Mbarara, Uganda. MUTH is the primary referral hospital for southwestern Uganda and currently serves more than 2 million people. The MUTH HIV/AIDS Clinic was founded in 1998 to provide outpatient care and resources for AIDS patients after discharge from the hospital. ART became available at the clinic in 2001. At this time, more than 9000 patients are being followed, 2500 of whom receive antiretroviral medications distributed through national and international sources.

The West Africa treatment setting is the HIV/AIDS Clinic at Jos University Teaching Hospital (JUTH), Jos, Nigeria. JUTH is the referral hospital for north central Nigeria; as such, it serves some 20 million people. The HIV/AIDS Clinic at JUTH was established in 1997, and the first patients were treated with combination ART that same year. Currently, more than 6000 patients are being followed at the JUTH HIV/AIDS Clinic. More than 4000 receive ART. A variety of formal adherence support activities, including professional and peer counseling, have also been initiated at this site.

Applying the Schema to the Information-Motivation-Behavioral Skills Model Using Information From the Ugandan and Nigerian Clinical Settings

We now illustrate use of the schema by applying it to the IMB model. To complete the illustrative validation exercise, we address each of the schema's 4 analytic questions, drawing on examples from the Ugandan and Nigerian clinical settings. The exercise is intended to provide a sense of what constitutes answers to the questions; it is not a full-scale sociocultural validation of the IMB model.

Question 1: Are the Model's Basic Concepts Relevant in the New Setting?

An important indicator of relevance for this individually centered model is whether its basic concepts are represented in the experience of patients. The IMB model's basic concepts were all reflected in the patient interviews conducted for our preliminary research. In patients' descriptions of their adherence experience, information was represented in the form of basic understanding of adherence requirements and the likely emergence of side effects. Statements indicative of commitment to adherence, confidence in the efficacy of antiretroviral medications, and anticipated benefits of taking these medications (eg, improved quality of life) testified to the IMB definition of motivation. Patients also pointed to a number of strategies they had devised for taking antiretroviral medications on schedule, demonstrating mastery of adherence-related behavioral skills. The following excerpts from patient interviews show how IMB appeared in the data:


“If I take them at 8:00, it's always at 8:00. I should not forget and start missing them. Before I take them, take some light food. Even if problems come, I still continue.”

“…my health providers have explained it to me. They told me to take them at the same time. Also told me some of the side effects I might get like dizzy, nausea, sometimes headache or diarrhea.”


“I will continue taking them until I die. This is because I love my life but also health.”

“[Before starting], I thought about death. Because at the time, I did not have the strength, not even to eat. But now, I take these drugs and I will live a better life. I believe I am going to be better and live for longer.”

“I hope that I am going to be better [from taking antiretroviral medications]. I think I will be strong again-I will start eating normally, get normal work, start getting money, whatever I want, because I will be strong. I will get back to taking care of my family.”

Behavioral Skills

“For us Muslims, every day we pray five times. In the morning I wake up to go to pray. At the morning prayer, I know I take a pill. Then at [the evening prayer], that's the time I take the night pill. The time of prayer helps me.”

“I have borrowed a radio. It helps me for time. At the English news, I remember, it's time to take the medicine.”

Question 2: Are Basic Concepts Important to the New Setting Represented in the Model?

Question 1 addresses the validity of an existing model's basic concepts. In question 2, we ask whether new concepts should be added. Answering this question requires understanding the new setting well enough to identify basic concepts needed for validity but not presently included in a particular model or to state with reasonable confidence that no additional basic concepts are needed. Our preliminary research results point to 3 conceptual domains that, if made more salient in the IMB model, might increase its validity for the Ugandan and Nigerian sociocultural settings. The domains are (1) access to therapy, (2) social context, and (3) culture.

Consistent access to therapy is a prerequisite for adherence. Access appears in the IMB model as a moderating influence on relations among basic concepts. In the African settings, patients have continued to encounter access barriers, even though the cost of medications is now subsidized. One such barrier is the difficulty of making clinic visits, which not only involve expensive transportation but require setting aside an entire day that would otherwise have been devoted to income-generating activity. Stock-outs are also a persisting access problem, despite the overall greater availability of antiretroviral medications.

Social context includes social structure (ie, the organization of social relations) and interpersonal ties. Social structural barriers to adherence do not appear in the IMB model but are evident in African settings. Poverty and gender inequality are 2 important structural barriers. Poverty in the form of food scarcity, for example, leads to chronic hunger. Hunger interferes with adherence by adding to the discomfort of taking antiretroviral medications, some of which can cause digestive or gastrointestinal distress. Patients whose regimens include medications to be taken with food may skip doses when they have nothing to eat. It is also poverty that renders costly clinic visits problematic.

Gender inequality (ie, subordination of women) influences adherence by impeding access. For example, when a husband and wife are both HIV-positive and the family can afford to support treatment for only 1 individual, that individual is likely to be the husband. Women who are economically dependent on their husbands are often reluctant to disclose being HIV-positive to their spouses for fear of abandonment, violence, and/or divorce. Reluctance to disclose seropositivity also impedes access.

Social context as interpersonal ties appears in the IMB model in the form of social support. The model casts social support as a moderating influence on the relations among IMB. In the Ugandan and Nigerian treatment settings, social support is provided by family members, friends, and/or acquaintances. The JUTH clinic is formalizing social support by identifying “treatment partners” for individual patients. Treatment partners are individuals who make formal commitments to assisting patients with adherence.

Culture is the set of rules and meanings that shape behavior and help to make sense of experience. Culture is manifested as norms, values, and meanings and is expressed through ethical, religious, knowledge, aesthetic, and healing systems.32 Culture is part of every society; however, it is easier to recognize in unfamiliar environments. Culture does not figure in the IMB model; yet, it clearly plays a role in shaping adherence. In the African context, a preference for traditional systems of healing over biomedicine is a potential adherence barrier that has its roots in culture, as is insistence on the part of Christian clergy that the “cure” for HIV/AIDS does come not from taking antiretroviral medications but from a faith in God.

Question 3: Are the Meanings of the Model's Basic Concepts Accurate for the New Setting?

This question focuses on the indicators through which basic concepts in a model are specified. For example, in the IMB model, as we have seen, one indicator of the concept of behavioral skills is the ability to perform necessary adherence-related tasks. Such tasks may include acquiring medications, coping with side effects, mobilizing social support for adherence, and self-administering therapy by, for example, putting reminders of or “cues to” dosing into place.29

Sociocultural differences in behavioral skills are evident at the indicator level. In the Ugandan and Nigerian settings, as we have seen, cues to dosing as adherence-related abilities were readily reported by patient interviewees, who cited radio news programs and Islamic daily prayer rituals as examples. Like their counterparts in other geographic areas, these patients looked to regularly scheduled events for dosing cues. What can be relied on to be regularly scheduled is different in different contexts, however. In resource-limited settings, radio programs and daily prayers33 may be more reliable than, for example, meal preparation as dosing cues.

Question 4: Does the Model Capture the Complexity of Adherence in the New Setting?

Adherence is widely acknowledged to be a complex process shaped by many barriers and facilitators. This is no less true in resource-limited sociocultural contexts. Much of this complexity typically disappears in the translation to representation, however, making it too easy to lose sight of essential ingredients of adherence processes and running the risk that resulting conceptualizations are too abstract to be illuminating.

The prospect of developing valid theoretic models of adherence for resource-limited settings offers a new opportunity to capture complexity. For a sense of what complexity might mean in the Ugandan and Nigerian contexts, let us consider the following example: cost of HIV/AIDS therapy.

Cost as a barrier to ART for HIV/AIDS in poor countries is cited with increasing frequency by researchers.34-36 With expanding access to subsidized therapy, however, we see that the cost of transportation and medication forms a “cost barrier.” A seemingly straightforward concept, “cost of transportation” is, in fact, complex. In Mbarara and Jos, it combines at least 4 factors: (1) long distances to be traveled to the clinic; (2) actual transportation expenses (eg, high rates charged by taxi drivers, cost of fuel for personal vehicles); (3) requirement of payment in cash, which is a substantial obstacle for farmers accustomed to acquiring goods and services through trade; and (4) the prospect of incurring these costs repeatedly and indefinitely as part of keeping regular clinic appointments. The more our theoretic models can capture this kind of complexity, the better they serve as guides to research and intervention.

A Word About Process

The preceding sections have been content focused in large part. In them, our intent has been to indicate what answers to the schema's 4 analytic questions might look like. In addition to the focus on content, however, some attention should be accorded to process. What overall form does our proposed approach to cross-cultural validation take?

The approach combines deductive and inductive analyses in an iterative fashion. Deductive analyses take the model being evaluated as their starting point, whereas inductive analyses begin from an understanding of the new sociocultural setting the model is intended to fit. An understanding of the setting is acquired principally through first-hand experience, which is the result of spending time observing, participating, and interpreting the results.

Addressing question 1, for example, requires a deductive analytic process in which the components of an existing model are examined for relevance using sociocultural knowledge. Question 2, in contrast, calls for an inductive approach in which the analyst adopts the perspective gained by acquiring sociocultural knowledge and, from that perspective, asks whether all concepts needed are represented. The inductive component of the approach is essential because it provides an analytic position outside the model from which to pose questions of validity. The entire process is iterative in that multiple applications of the schema are likely to be needed to produce strong and precise validation results.


Meaningful research and intervention efforts to support adherence to antiretroviral medications in resource-limited settings require valid theoretic models. New models may be constructed for such settings, or existing models may be applied. Before applying existing models in new sociocultural contexts, they should be examined for validity and adapted as necessary for a good fit. Our intent here has been to offer a set of practical conceptual tools for examining adherence models for cross-cultural validity.


The contribution of Toni Tugenberg, LICSW, to the preparation of this manuscript is gratefully acknowledged by the authors. Thanks are extended to John Idoko, MD, and Irene Andia, MMed, for helping to make the research and writing possible. Maryam al-Mansur, MD, provided information for some of the examples.


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adherence; antiretroviral therapy for HIV/AIDS; cross-cultural validation; East Africa; theoretic model; West Africa

© 2006 Lippincott Williams & Wilkins, Inc.