Major Finding: Nonadherence rates for antiepileptic medication reached 58% in the first 6 months after epilepsy diagnosis.
Data Source: A 6-month, single-center study of 124 children with newly diagnosed epilepsy.
Disclosures: The study was funded by a grant from the National Institutes of Health. Dr. Modi disclosed that she has been a consultant for Novartis Pharmaceuticals. Another study author disclosed speaker and adviser relationships with companies that manufacture antiepileptic drugs.
Some level of nonadherence to antiepileptic drug monotherapy was apparent in four of five adherence trajectories described in a single-center study of 124 children with newly diagnosed epilepsy.
Based on these findings, “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,” wrote Avani C. Modi, Ph.D., and her co-authors at Cincinnati Children's Hospital Medical Center.
They reported that the five trajectories included “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 (JAMA 2011;305:1669–76).
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.
The children in the current study 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%).
A majority of the patients (60%) received carbamazepine, and others received valproic acid.
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.
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 said that those two groups are the children and families 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.”
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.