Asthma epidemiology reports – February 2, 2010

Reduction in Asthma Hospitalizations, Definitions of Childhood Asthma; Confirmation of Asthma; Adult Asthma Trends

Rapid reduction in hospitalizations after an intervention to manage severe asthma (ERJ – Souza-Machado et al.) – Evaluation of the Programme for Control of Asthma in Bahia (ProAR) which focused on providing free management of severe asthma. Achieved an 82% decline in asthma hospital admissions between 1998-2006, and report an “inverse correlation between provision of medication for asthma and hospitalization.”

Different definitions in childhood asthma: how dependable is the dependent variable? (ERJ – van Wonderen et al.) – Amazing review of 122 papers yielded 60 different definitions of asthma. “Prevalence estimates varied between 15.1% and 51.1% depending on the asthma definition used. The percentage of children whose posterior asthma probability was in the area of clinical indecision varied from 14.9% to 65.3%.” Conclusion – “Variation in definitions and its effect on the performance of prediction models may be another source of otherwise inexplicable variation in daily clinical decision making.”

Confirmation of Asthma in an Era of Overdiagnosis (ERJ – Luks et al.) – Following up on their recent report that 30% of adults with a physician diagnosis of asthma did not have asthma when objectively assessed, this article demonstrates that, “For the majority with a previous physician diagnosis of asthma only pre- and post- bronchodilator spirometry and a single methacholine challenge test are required to confirm asthma.”

Changes in the Prevalence of Asthma in Adults since 1966: The Busselton Health Study (ERJ – James et al.) – Cross-sectional respiratory health surveys of Busselton adults conducted in 1966, 1969, 1972, 1975, 1981, 1990 and in 2005-07 indicate that increased rates of doctor-diagnosed asthma are “partly explained by increased symptoms and atopy”; however, “factors such as diagnostic transfer and increased awareness of asthma have also contributed to the rise in prevalence.”