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

Abstract

Examine preventive medication adherence among youth with migraine. 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. 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. Youth with migraine can demonstrate and sustain relatively high levels of medication adherence over the course of a clinical trial.