Multimodal Assessment of Medication Adherence Among Youth With Migraine: An Ancillary Study of the CHAMP Trial

Abstract

Objective: Examine preventive medication adherence among youth with migraine.

Methods: Adherence (self-report, pill count, and blood serum drug levels) was assessed as an ancillary study that utilized data from 328 CHAMP Study participants (ages 8-17). CHAMP was a multisite trial of preventive medications. Participants completed a prospective headache diary during a six-month active treatment period during which youth took amitriptyline, topiramate, or placebo pill twice daily. Self-reported medication adherence was collected via daily diary. At monthly study visits, pill count measures were captured. At trial month 3 (trial midpoint) and 6 (end of active trial), blood serum drug levels were obtained. Self-report and pill count adherence percentages were calculated for the active trial period, at each monthly study visit, and in the days prior to participants' mid-trial blood draw. Percentages of nonzero drug levels were calculated to assess blood serum drug level data. Adherence measures were compared and assessed in context of several sociodemographic factors. Multiple regression analyses investigated medication adherence as a predictor of headache outcomes.

Results: Self-report and pill count adherence rates were high (over 90%) and sustained over the course of the trial period. Serum drug level adherence rates were somewhat lower and decreased significantly (from 84% to 76%) across the trial period [t (198) = 3.23, p = .001]. Adherence measures did not predict headache days at trial end; trial midpoint serum drug levels predicted headache-related disability.

Conclusions: Youth with migraine can demonstrate and sustain relatively high levels of medication adherence over the course of a clinical trial.

Trial registration: ClinicalTrials.gov NCT01581281.

Keywords: adherence/self-management; adolescents; clinical trial; headache and migraine; school age children.

© The Author(s) 2021. Published by Oxford University Press on behalf of the Society of Pediatric Psychology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Figures

Figure 1.

Schematic of CHAMP trial procedure. During the 8-week long titration period, dosage of study drug was increased every 2 weeks until desired or most tolerated dosing (target of 1 mg/kg daily for amitriptyline; 2 mg/kg daily for topiramate) was achieved. The duration of this titration phase was modified based on tolerability, and could extend to 10 weeks. Subsequently, participants were kept at a constant dose of study drug over the course the maintenance period, and then weaned off of medication for ∼2 weeks. A safety phone call was completed 4 weeks after participants were successfully weaned off of medication to terminate the study. The vast majority of participants were able to successfully continue with the trial on a maximum tolerable dose (∼5% of participants discontinued due to side effects; Powers et al., 2017).

Figure 2.

(a) Self-reported Adherence Percentages across CHAMP Trial Months, Shown with 95% confidence intervals. (b). Pill Count Adherence Percentages across CHAMP Trial Months, Shown with 95% confidence intervals. *denotes confidence interval nonoverlapping (indicating a significant difference) with other adherence measure from same month of CHAMP trial; + denotes confidence interval nonoverlapping with same adherence measure at a different month in trial period.