Rates and correlates of relapse following ED discharge for acute asthma: a Canadian 20-site prospective cohort study.

BACKGROUND: Acute asthma is a common ED presentation. In a prospective, multicenter cohort study, we determined the frequency and factors associated with asthma relapse following discharge from the ED.

METHODS: Adults aged 18 to 55 years who were treated for acute asthma and discharged from 20 Canadian EDs underwent a structured ED interview and a follow-up telephone interview 4 weeks later. Standardized antiinflammatory treatment was offered at discharge. Multivariable analyses were performed.

RESULTS: Of 807 enrolled patients, 58% were women, and the median age was 30 years. Relapse occurred in 144 patients (18%) within 4 weeks of ED discharge. Factors independently associated with relapse occurrence were female sex (women, 22% vs men, 12%; adjusted OR [aOR], 1.9; 95% CI, 1.2-3.0); symptom duration of ≥ 24 h prior to ED visit (long duration, 19% vs short duration, 13%; aOR, 1.7; 95% CI, 1.3-2.3); ever using oral corticosteroids (ever use, 21% vs never use, 12%; aOR, 1.5; 95% CI, 1.1- 2.0); current use of an inhaled corticosteroid ([ICS]/long-acting β-agonist combination product (combination product, 25% vs ICS monotherapy,15%; aOR, 1.9; 95% CI, 1.1-3.2); and owning a spacer device (owning one, 24% vs not owning one, 15%; aOR, 1.6; 95% CI, 1.3-1.9).

CONCLUSIONS: Despite receiving guideline-concordant antiinflammatory treatments at ED discharge, almost one in five patients relapsed within 4 weeks. Female sex, prolonged symptoms, treatment-related factors, and markers of prior asthma severity were significantly associated with relapse. These results may help physicians target more aggressive interventions for patients at high risk of relapse.