The investigators hypothesized that several factors would predict better continuity with medication, including:
- Greater acceptance of the need for treatment by the child;
- Parental belief that ADHD has a long-term course; and
- A greater working alliance with the child’s provider.
The children were all from the greater Cincinnati area and seen between 2010 and 2013. All were English-speaking, 6-10 years old at the time of their initial diagnosis, and medication-naive. Patients and parents completed a baseline assessment set of surveys and tests, which were repeated in 3 months. Eighteen months after therapy was started, the researchers completed a retrospective review of pharmacy dispensing records for each child in the study.
The baseline assessment included parental measures of literacy and numeracy, a measure of psychological distress, quality-of-life assessments, and measures of child behavior and symptoms specific to ADHD. Parents also completed a scale that evaluated perception of primary care and satisfaction with the information provided at the initial visit. Finally, the parents and the patient also completed baseline measures to assess beliefs about ADHD, acceptance of medication, comfort with the decision to treat, and beliefs about the potential benefits of medications. Another tool evaluated the working relationship between parents and the providers. During the study, subjects completed tools to assess perceived side effects from medication.
In addition to looking at dispensing, the 18-month chart review looked at number of visits, number of prescriptions written, any titration of the child’s regimen in the first 3 months of treatment, appropriate monitoring if the child had a visit within 30 days of the initial prescription, and the frequency of monitoring thereafter either by phone or by in-person visits.
The main adherence outcomes were the medication coverage in the first 90 days, as well as medication coverage from days 91 to 450. The children, 89 in total with a median age of 8.3 years at the time of enrollment, were drawn from 44 pediatricians and 11 practices in the area. Clustering among practices and providers was accounted for in the analyses. The majority (71%) of the children were white. Just over one third (38%) received public insurance.
The majority of the children (90%) received an extended-release stimulant as their initial medication; 7% received an immediate-release stimulant, and the remainder other medications.
Predictors of continuity of medication in the first 90 days included parental satisfaction with the information received; receiving at least one medication titration; better reduction in symptoms; parental beliefs about ADHD; and, surprisingly, a lower working alliance with the provider. Those variables together accounted for about one third of the variation in medication continuity among the children. During that first 90-day period, the median number of days covered across all groups was 81%.
Only 54% of days were covered during the period from 91 to 450 days. The main predictors of adherence during that period were the child’s acceptance of medication and the difference between the parents’ perception of the need for treatment of ADHD versus their concerns about ADHD medication. Not surprisingly, there was a negative correlation between the child’s dislike of medication and adherence.
The authors concluded that medication adherence among children treated for ADHD can be influenced by several modifiable practices. The predictors of short-term adherence are not the same as the predictors of long-term adherence.