Theoretical Models of Health Behavior
Theoretical Models of Health Behavior
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Medication adherence, especially in children and adolescents, is a complex problem that is poorly understood and underresearched, yet it is a clear barrier to effective treatment and is frequently encountered in everyday clinical practice. In pediatric populations, the relationship between the prescribed treatment and the treatment implementation is further complicated by parents, who usually are the decision makers for the young patient.
While it is often possible to identify children and families at risk for poor medication adherence, it is not always clear to medical professionals how best to use this information. This article examines 4 empirically supported theoretical models of health behavior and applies them to the treatment adherence literature that is available for children and adolescents who take stimulants for attention-deficit/hyperactivity disorder (ADHD). Clinical examples will illustrate how these models can be used to improve medication adherence in young patients.
The problem of poor adherence
The dilemmas inherent in medication adherence are particularly stark in the use of psychostimulants for children and teens who have ADHD. Research has shown that psychostimulants (ie, methylphenidate, dextroamphetamine, and mixed amphetamine salts) are clearly beneficial for reducing symptoms characteristic of ADHD—inattention, overactivity, and impulsivity.1
However, in community samples, patients took stimulant medication on average for about 3 to 4 months following the first prescription, compared with patients in clinical research samples, who took medication for about 2 to 6 years.2-6 Adherence to stimulant medication also declines with age, with adherence rates decreasing from 72% at age 11 years to 32% at age 15 years.7 Clinical treatment guidelines recommend that physicians pay close attention to medication adherence, noting that poor treatment adherence contributes to poor response.8
The Table summarizes factors associated with decreased adherence to psychostimulants. The likelihood that patients will use stimulant medication generally can be identified at the initial diagnostic assessment. Parents who understand that ADHD is a biological disorder and believe that the medications are safe and effective are the most likely to support their use in their children’s treatment regimen, especially for children whose symptoms are more severe.
In a survey by Charach and colleagues,9 parents described the choice to have their child with ADHD treated with psychostimulants as a difficult one. Once the child has tried the medication, clear symptom benefit with few adverse effects and a simplified dosing schedule encourages families to continue its use (see Charach and Gajaria10 for a more thorough discussion of predictors of stimulant adherence). However, many families do not find the use of stimulant medication by their child to be straightforward. Two cognitive behavioral models, the Health Beliefs Model (HBM) and the Theory of Reasoned Action and Planned Behavior (TRAPB), address the beliefs and behavior of the parents and the child at a given point.11,12
Health Beliefs Model
The essential focus of the HBM is the preference to use or not to use stimulant medication based on the family’s perception of risks and benefits (Figure 1). Consistent with this model, severity of ADHD symptoms along with comorbidities influence the parents’ beliefs about how much benefit medication might offer. Applying the HBM provides a method of educating patients and their parents by eliciting their beliefs about the origins of the difficulties. By describing the potential benefits and harms of treatment, the discussions can shape parents’ attitudes by increasing their knowledge.
Parents often express concerns about adverse effects, especially physiological effects.9,13,14 When the family is willing to initiate medication, the physician can address these concerns by discussing adjustments to the dose or dosage or by changing to a different agent.
Susie is an 8-year-old third grader who lives with her parents and a younger brother. Her second-grade teacher had reported that Susie often had trouble focusing on her work and completing assignments. The teacher thought that Susie could do better and suggested a psychoeducational evaluation. Organizational and working memory difficulties were noted but no learning disability, which is consistent with primarily inattentive-type ADHD.
Susie’s parents were hesitant about having their daughter take a stimulant medication. They found the teacher to be young and inexperienced and felt that better teaching methods and extra tutoring were preferable for Susie’s learning problems. In addition, her mother was concerned that Susie, who had always been a picky eater, would have even more trouble eating if she were to use stimulant medication.
After a thorough discussion of the pros and cons of an educational versus a pharmacological approach that would include stimulant medication, the physician and family agreed to educational supports.
Theory of Reasoned Action and Planned Behavior
The second cognitive-behavioral model, TRAPB, includes aspects of the HBM but uniquely focuses on the gap between the patient’s intention to follow the treatment plan and actual pill-taking behavior (Figure 2).12 More recently, Reach15 identified the role of routine habit as an important component of this model. Activities that assist young people in integrating the taking of their medication into their daily routine can help. For example, the match between pills prescribed and pills taken improves when long-acting stimulants are used because they simplify the dose schedule.7
Parental supervision, daily medication routines, and memory aids for children and parents with poor organization skills also are helpful. In the following case vignette, Robert’s mother had assisted him by reminding him to take his medication; now that he is older, however, her reminders are of little use unless they match his intentions.