According to results of a historical cohort study, adherence to inhaled corticosteroid (ICS) treatment is not associated with a decreased occurrence of exacerbations in asthmatic patients with elevated blood eosinophil levels.

The study aimed to determine the association between ICS therapy adherence and the occurrence of asthma exacerbations in patients with high blood eosinophil levels. The authors utilized the Optimum Patient Care Research Database to identify patients ≥18 years old who were classified as steps 3 or 4 according to the Global Initiative for Asthma with ≥2 ICS prescriptions in the year prior to clinical review. The study authors explained, “Patient characteristics and adherence (based on prescription refills and patient self-report) for ICS therapy were analyzed for those with elevated (>400 cells/μL) or normal (≤400 cells/μL) blood eosinophils.”

Of the total of 7195 patients identified and enrolled in the study, 66% were female and their average age was 60 years old. The median eosinophil count of the patients was 200 cells/mL and 81% of the patients were not fully adherent to ICS therapy. 

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Of the 1031 patients (14%) with elevated blood eosinophil counts, 83% were found to not be fully adherent to ICS therapy. It was also reported that, among patients with elevated eosinophil levels, a larger proportion who were adherent to therapy experienced ≥2 exacerbations (14.0% vs 7.2%; P=.003) and uncontrolled asthma (73% vs 60.8%; P=.004) compared with those who were not fully adherent to therapy.

“Adherence to ICS therapy was not associated with decreased exacerbations for these patients,” the study authors concluded. They added, “Additional therapy should be considered for these patients, such as biologics, which have been previously shown to improve control in severe uncontrolled eosinophilic asthma.”


Papi A et al. Relationship of inhaled corticosteroid adherence to asthma exacerbations in patient with moderate-to-severe asthma. Journal of Allergy and Clinical Immunology. DOI: 10.1016/j.jaip.20118.03.008.