Objectives: The objectives were to determine patient and treatment-response factors associated with relapse after emergency department (ED) treatment for acute asthma.

Methods: Subjects aged 18-55 years who were treated for acute asthma in 20 Canadian EDs prospectively underwent a structured ED interview and telephone contact 2 weeks later.

Results: Of 695 enrolled patients, 604 (86.9%) were discharged from the ED; follow-up was available in 529 (87.5%); 63% were female and the median age was 29 years. Most patients were discharged on oral (70.8%) and inhaled (60.1%) corticosteroids (CS); 2-week treatment adherences were 93.3 and 80.9%, respectively. Relapse occurred in 9.2% at 1 week (95% confidence interval [CI] = 7.1% to 12.0%) and 13.9% (95% CI = 11% to 17%) at 2 weeks. In multivariable modeling, factors associated with relapse were ethnicity (risk ratio [RR] white = 0.66; 95% CI = 0.52 to 0.83); female gender (RR = 1.57; 95% CI = 1.14 to 2.09); any ED visits in the past 2 years (RR = 1.47; 95% CI = 1.18 to 1.80); ever admitted for asthma treatment (RR = 1.83; 95% CI = 1.09 to 2.84); use of combined inhaled CS plus long-acting beta(2)-agonists (RR = 1.39; 95% CI = 1.07 to 1.78) and of oral CS (RR = 1.35; 95% CI = 1.12 to 1.59) at the time of ED presentation.

Conclusions: Ethnicity (white), female gender, prior ED visits and admissions for asthma, and recent treatments (especially oral CS) were associated with asthma relapse, which remains relatively common. Future research is required to target this high-risk group.

Authors: Brian H Rowe, Cristina Villa-Roel, Marco L A Sivilotti, Eddy Lang, Bjug Borgundvaag, Andrew Worster, Allan Walker, Scott Ross