Abstract
PURPOSE: It is unclear how often adolescents with persistent asthma know when to use different inhaled medications (as-needed rescue vs. daily controller; 'accurate use'), or whether this knowledge is associated with clinical asthma outcomes. This study aimed to characterize adolescent knowledge of accurate use; examine whether accurate use is associated with controller medication adherence, asthma symptoms, or exacerbations requiring acute health care services; and determine whether knowledge of accurate use improves following regular exposure to controller medications with school-based directly observed therapy (DOT). METHODS: We analyzed baseline and 7-month data from the School-Based Asthma Care for Teens trial. Adolescents (12-16 years) identified inhaled medications on a chart and stated when each is used. We compared accurate use with adolescent-reported adherence, recent symptoms, and asthma-related acute health care visits; and exposure to DOT. Analyses were limited to subjects with controller medication. RESULTS: Of 430 participants, 252 had controller medication at baseline. Knowledge of accurate use was described by 62%, and associated with adherence (odds ratio [OR]: 2.06, 95% confidence interval [CI]: 1.12-3.83). By 7 months, 313 adolescents had controller medication; 75% described accurate use, which was associated with adherence (OR: 3.46, 95% CI: 1.83-6.54), health care (OR: 0.39, 95% CI: 0.20-0.79), and DOT exposure (OR: 1.83, 95% CI: 1.10-3.32). Associations with adherence and health care at 7 months persisted in adjusted analyses. DISCUSSION: Adolescent knowledge of accurate medication use was linked with greater adherence (baseline, 7 months), less acute health care (7 months), and exposure to in-school DOT. Interventions to support adolescents with persistent asthma should consider school-based care strategies and facilitate adolescent understanding of when to use different medications.