Relationship of inhaled corticosteroid adherence to asthma exacerbations in patients with moderate to severe asthma

Publication date: Available online 5 April 2018
Source:The Journal of Allergy and Clinical Immunology: In Practice
Author(s): Alberto Papi, Dermot Ryan, Joan B. Soriano, Henry Chrystyn, Leif Bjermer, Roberto Rodríguez-Roisin, Myrna B. Dolovich, Mark Harris, Lucy Wood, Maria Batsiou, Susannah I. Thornhill, David B. Price
BackgroundPatients with asthma and elevated blood eosinophils are at increased risk of severe exacerbations. Management of these patients should consider non-adherence to inhaled corticosteroid (ICS) therapy as a factor for increased exacerbation risk.ObjectiveTo investigate whether poor adherence to ICS therapy explains the occurrence of asthma exacerbations in patients with elevated blood eosinophil levels.MethodsThis historical cohort study identified patients within the Optimum Patient Care Research Database, aged ≥18 years, at Global Initiative for Asthma (GINA) steps 3 or 4, with ≥2 ICS prescriptions during the year prior to clinical review. Patient characteristics and adherence (based on prescription refills and patient self-report) for ICS therapy were analysed for those with elevated (>400 cells/μL) or normal (≤400 cells/μL) blood eosinophils.ResultsWe studied 7,195 patients (66% female, mean age 60 years) with median eosinophil count of 200 cells/μL and found 81% to be non-fully adherent to ICS therapy. 1,031 patients (14%) had elevated blood eosinophil counts (58% female, mean age 60 years), 83% of whom were non-fully adherent to ICS. An increased proportion of adherent patients in the elevated blood eosinophil group had ≥2 exacerbations (14.0% vs 7.2%; p=0.003) and uncontrolled asthma (73% vs 60.8%; p=0.004) as compared to non-fully adherent patients.ConclusionsApproximately one in seven patients had elevated eosinophils. Adherence to ICS therapy was not associated with decreased exacerbations for these patients. Additional therapy should be considered for these patients, such as biologics, which have been previously shown to improve control in severe uncontrolled eosinophilic asthma.