Variability in asthma: symptom perception, care, and outcomes

Asthma remains a global respiratory health concern. Substantial variations in asthma outcomes persist in Canada despite the dissemination of national management guidelines. Many factors and their interactions presumably contribute to variations in outcomes, including asthma prevalence, severity, symptom recognition, self-management behaviour, access to care, and management. This article reviews the physiology of symptom perception in asthma, specifically the role of dynamic lung hyperinflation (DH) on the perception of the intensity and quality of dyspnea in asthma, and the link between blunted perception and life-threatening asthma. Additionally, the magnitude and correlates of regional variation in emergency department visit rates and hospitalizations for asthma in Ontario are reviewed.