Higher socioeconomic status was associated with better adherence to antiepileptic medication during a 6-month, single-center study of 124 children with newly diagnosed epilepsy.
Avani C. Modi, Ph.D., and her colleagues at Cincinnati Children’s Hospital Medical Center reported that five adherence trajectories characterized the children’s adherence levels for twice-daily medication: "severe early nonadherence" for 13% of patients, "severe delayed nonadherence" for 7% of patients, "moderate nonadherence" for 13%, "mild nonadherence" for 26%, and "near-perfect adherence" for 42%. The authors described the study as the first to examine adherence trajectories for children with epilepsy.
According to this group-based trajectory modeling, almost 60% of the patients were nonadherent for the first 6 months of treatment. This was a "surprising" figure, given the results of the investigators’ previous study, which found a nonadherence rate of 20% in the first month of treatment, they wrote in a report published online April 27 in JAMA.
Prior cross-sectional studies of children with epilepsy have described self-reported nonadherence rates of 12%-35%, but they had "major methodological problems," according to the authors.
They advised that "clinicians should consider routinely assessing adherence to antiepileptic drug therapy in all children with epilepsy. Self-report measures of adherence have recently been developed for children with epilepsy and could be used in routine clinical care."
The children had a mean age of 7.2 years (range of 2-12 years) and 64% of them were male. The cohort was 76% white, 17% black, 7% biracial or multiracial, and 1% Asian; 3% were Hispanic. Nearly half of the cohort had idiopathic localization-related epilepsy (48%), and others had idiopathic generalized epilepsy (19%), idiopathic unclassified epilepsy (15%), cryptogenic localization-related epilepsy (8%), cryptogenic generalized epilepsy (5%), symptomatic localization-related epilepsy (5%), or symptomatic generalized epilepsy (1%). (Percentages do not equal 100% because of rounding.)
A majority of the patients (60%) received carbamazepine, and others received valproic acid.
To measure socioeconomic status, the investigators calculated occupation-based Duncan scores for each family. The mean score was 52, reflecting "occupations such as office supervisor, mail carrier, firefighter, and police officer." An electronic monitoring system measured adherence rates by recording when the medicine bottle was opened or closed.
During follow-up appointments at 1 month post diagnosis and every 3 months thereafter, a pediatric epileptologist or pediatric epilepsy nurse practitioner recorded seizure frequency, adverse events, and any change in medication for controlling seizures or reducing intolerable adverse events.
Dr. Modi and her associates found no effect on adherence rates by other variables such as age, sex, caregiver marital status, seizure type and frequency, initial and total number of antiepileptic medications, frequency of adverse events, and who first observed the child’s seizure (JAMA 2011;305:1669-76).
The five adherence groups exhibited significant intra- and interpatient variability, according to the investigators. Children who had severe early nonadherence "took between one-quarter and one-half of their antiepileptic drug doses in the first month of therapy and then became completely nonadherent over time, suggesting ‘volitional’ nonadherence, wherein parents may have actively decided that their children should not take antiepileptic drugs based on reasoned decisions."
Children in the severe delayed nonadherence group initially had about 90% adherence, but that gradually declined to about 20% after 6 months. This decline "may reflect caregivers who occasionally missed giving antiepileptic drug doses with no major health consequence (e.g., seizure) and, thus, made decisions to discontinue antiepileptic drugs."
Dr. Modi and her coauthors described those two groups as the children and families who are in greatest need of "adherence interventions focused on discussing the family’s beliefs regarding epilepsy and antiepileptic drugs and providing education about treatment misconceptions."
Children in the moderate nonadherence group, which averaged taking about 70% of their doses, may have missed taking their medication in blocked periods of time such as on vacations and during weekend sports, and "would benefit from problem-solving regarding barriers to adherence and instituting general behavioral and organizational strategies."
Although children in the mild nonadherence group had a stable adherence rate of 85%, the authors noted that it is unknown if this rate is "sufficient to maintain the therapeutic benefit of antiepileptic drugs for this period."
The investigators wrote that the "often intrinsic link between socioeconomic status and education" makes it plausible that the limited financial resources of many of the families of children that fell into groups with mild or worse rates of nonadherence affect tangible aspects of poor adherence, such as the inability to pay for medications, as well as the intangible aspects, such as parental supervision. "Proactive adherence promotion efforts are particularly salient for families who are economically disadvantaged," they wrote.