Purpose: The purpose of this study was to monitor medication adherence in cystic fibrosis (CF) patients and its correlation with disease severity and patient age.
Methods: Children less than 12 years of age (group 1) and adolescents 12 years of age and older (group 2) were recruited from the University of Michigan CF Center. The study duration was 3 months. A total of 22 patients per group were enrolled. Adherence to ADEKs, an oral multivitamin, and dornase alfa, a nebulized mucolytic medication, was monitored. Adherence to ADEKs was monitored by using the Medication Event Monitoring System (MEMS) SmartCaps (APREX, AARDx, Inc., Union City, California). Dornase alfa adherence rate was monitored by counting empty medication vials.
Results: Thirty-three patients completed the study, 15 patients in group 1 and 18 patients in group 2. The overall mean adherence rates for ADEKs and dornase alfa were (+/- SD) 63.6% +/- 24.0% and 66.5% +/- 31.2%, respectively. The median ADEKs and dornase alfa adherence rate for group 1 was 84.6% and 79.1%, respectively (p = .08); and for group 2 was 56.7% vs. 78.4%, respectively (p = .07). There was a trend toward significance, suggesting that the adherence rate for ADEKs was higher than for dornase alfa (p = .08) in group 1. Group 2 showed a trend toward adherence to dornase alfa than to ADEKs (p = .07). There was a trend for ADEKs adherence between groups 1 and 2 (p = .09), but not for dornase alfa (p = .93).
Conclusion: Parental supervision and disease severity are likely to play a major role in adherence to medical management. Partnership with patients and families about the treatment plan might be important for improving adherence rate. The MEMS SmartCaps is an electronic monitoring technology that should be used to measure drug adherence objectively both in further larger clinical trials and in the outpatient setting.