ABSTRACT
Background: A “frequent exacerbator phenotype” has been described, mostly in the population of patients with severe asthma. Further data are needed on such exacerbation-prone patients in milder asthma. Aim: To compare the characteristics of frequent and nonfrequent exacerbators in asthma of different severities and to assess the stability of the exacerbator status. Methods: This was an observational study comparing baseline data from frequent (≥2 exacerbations in the past year) and nonfrequent (<2 exacerbations in the past year) exacerbators. Patients were also followed up for one year. Information regarding clinical, physiologic, and inflammatory characteristics was collected at baseline and one-year follow-up. Results: Forty-seven frequent and 53 nonfrequent exacerbators were recruited. No specific clinical, physiologic, or inflammatory characteristic was observed in the frequent as compared to the nonfrequent exacerbators at baseline. Fifty-eight percent of patients reporting frequent exacerbations at baseline remained in this group after one year of follow-up. Forty-two and 62% of patients with, respectively, mild-to-moderate asthma and severe asthma had frequent exacerbations. In a post hoc analysis according to asthma severity, frequent exacerbators with severe asthma had a higher body mass index and poorer asthma control, although they reported higher adherence to medication, in comparison to frequent exacerbators with mild-to-moderate asthma. No specific characteristics could discriminate between frequent and nonfrequent exacerbators of the same asthma severity. Conclusions: Frequent exacerbators with severe asthma present some specific characteristics not observed in frequent exacerbators with mild-to-moderate disease. However, the latter group should be identified to reassess treatment needs and potential contributing factors.
Acknowledgements
The authors thank Serge Simard for statistical analyses.
Declaration of interest
ME Boulay, C Pruneau-Pomerleau, F Deschesnes, H Villeneuve, and L Ringuette report no conflicts of interest. The authors alone are responsible for the content and writing of the paper. LP Boulet has the following potential conflicts of interest (last 3 years): Nonprofit Grants: Research funding provided to my center for participating in multicenter studies: These have mostly been performed in the context of the Canadian Network of Centres of Excellence “AllerGen” Projects: Altair, Amgen, Asmacure, AstraZeneca, Boehringer-Ingelheim, Boston Scientific, Genentech, GlaxoSmithKline, Novartis, Ono, Pharma, Schering, Wyeth. Support for Investigator Generated studies: Takeda, Merck, Boehringer-Ingelheim. Consulting/advisory boards: Astra Zeneca, Novartis, Methapharm. Royalties: Co- author for “Up-To-Date” card on occupational asthma. Patents: None. Nonprofit Grants for production of educational materials: AstraZeneca, GlaxoSmithKline, Merck Frosst, Boehringer-Ingelheim, Novartis. Speaking Activities: Lecture fees from AstraZeneca, GlaxoSmithKline, Merck, Novartis. Travel sponsorship to meetings for presentation of studies & Committees: Novartis, Takeda. Others: Member of the Canadian Thoracic Society Respiratory Guidelines Committee; Chair of GINA Guidelines Dissemination and Implementation Committee; Laval University Chair on Knowledge Transfer, Prevention and Education in Respiratory and Cardiovascular Health.