Factors Related to Biologic Adherence and Outcomes Among Moderate-to-Severe Asthma Patients.

Background: Adherence barriers to asthma biologics may not be uniform across administration settings for patients with moderate-to-severe asthma.

Objective: To examine differences in asthma biologic adherence and associated factors, as well as association with a 1-year all-cause emergency department (ED) visit, across administration settings.

Methods: A retrospective study of biologic naïve moderate-to-severe asthma patients with initial biologic therapy between January 1, 2016, and April 30, 2020, in the Optum Clinformatics Data Mart was performed. Three administration settings were identified: Clinic-only (outpatient office/infusion center), Home (self-administration), and Hybrid setting (mixture of clinic and self-administration). Asthma biologic adherence was the proportion of observed over expected biologic dose administrations received within 6 months from initial therapy. Factors associated with adherence were identified by administration setting, using Poisson regression analyses. A relationship between a 1-year all-cause ED visit and adherence was assessed for each administration setting using Cox regression analyses.

Results: The study cohort was 3932 patients. Biologics adherence was 0.75 [0.5, 1] in Clinic setting, the most common administration setting, and 0.83 [0.5, 1] in both Home and Hybrid settings. Specialist access was consistently associated with better biologic adherence, whereas Black race, Hispanic ethnicity, lower education, Medicare only insurance, and higher patient out-of-pocket cost were associated with worse biologic adherence in some settings. In the Hybrid setting, hazard for a 1-year all-cause ED visit decreased with biologic adherence.

Conclusions: Asthma biologic adherence varied by administration setting. Efforts to improve asthma biologic adherence should consider promoting self-administration when beneficial, improving prior specialist access, and targeting patients with higher risk of suboptimal adherence particularly Black and Hispanic patients.