Adherence to omalizumab: A multicenter 'real-world' study

Background: Adherence to medications is crucial in patients with severe asthma in light of the negative clinical impact and costs of non-adherence. Adherence to omalizumab has not been well studied in real-world settings. The aim of this study was to assess adherence to omalizumab and evaluate treatment effectiveness in relation to adherence. Methods: This was a retrospective, observational, and multicenter real-world study. Omalizumab dose, timing of administration, and duration of treatment ( 4 years) were analyzed. Adherence was evaluated by examining rates of expected and missing doses. Good adherence (10% doses missed) were determined. For effectiveness in relation to adherence of omalizumab we considered asthma exacerbations, hospitalizations, asthma control test (ACT), and Forced Expiratory Volume in 1 s (FEV1). Results: A total of 196 patients were evaluated, and 161 were suitable for data analyses. Good adherence was shown in 90.7% of patients and poor adherence in 9.3%. Considering adherence in relation to treatment duration: 4 years, 100% were adherent (expected doses, 6120; missed doses, none). Indices of efficacy between pre- and post-treatment showed significant improvement (p