Assessment of Medication Adherence and Related Factors in Children and Adolescents with Cystic Fibrosis: A Pharmacist-Led Study

Abstract

Background: Medication non-adherence in cystic fibrosis (CF) can lead to reduced drug efficacy and suboptimal care. Objectives: This study aimed to evaluate adherence to commonly used medications and related factors among children and adolescents with CF. Methods: A research pharmacist assessed drug adherence using the 5-item Medication Adherence Rating Scale (MARS-5) through face-to-face interviews with patients and their parents. Based on the MARS-5 score, patients were categorized as having perfect (>= 25) or lower (< 25) treatment adherence. Results: A total of 300 patients were included in the study. Between 42.0 and 87.9 of patients were lower-adherent in at least one aspect of their treatment. Among those who received all medications, 86.9 were lower-adherent. Specifically, 42.0 of patients had lower adherence to inhalants, 67.6 to systemic antibiotics, 81.4 to gastrointestinal agents, and 87.9 to nutritional supplements. Factors significantly associated with adherence included the number of drugs for inhalants and systemic antibiotics; the mother's education level for inhalants, systemic antibiotics, and gastrointestinal agents; and distance from the medical center for inhalants and nutritional supplements (all P < 0.05). Conclusions: Non-adherence to inhalants, systemic antibiotics, gastrointestinal agents, and nutritional supplements is common among children and adolescents with CF. Adherence to one class of medication does not predict adherence to others. A high number of drugs, a low mother's education level, and a long distance from the medical center decrease the likelihood of perfect adherence to CF medications.