Trends in the age of diagnosis of childhood asthma.

Background: The cause of rising asthma incidence over time remains unexplained. Examining trends in the age of diagnosis across successive birth cohorts may offer insights into asthma etiology.

Objective: To examine trends in the age at asthma diagnosis and the age and proportion of children hospitalized at first asthma diagnosis in Ontario, Canada.

Lower airway nitric oxide is increased in children with sickle cell disease.

Objectives: To determine alveolar and airways nitric oxide (NO) levels in children with sickle cell disease (SCD).

Study Design: Multiple flows fractional exhaled NO (FE(NO)), bronchial NO flux (J'aw(NO)), and alveolar NO concentration (Ca(NO)) were determined prospectively in 16 non-atopic children with SCD in a tertiary ambulatory clinic and compared with those in 10 children with primary ciliary dyskinesia and 22 healthy control subjects. Differences in FE(NO), J'aw(NO), and Ca(NO) were compared with mixed model analysis and Mann-Whitney tests.

Non-tuberculous mycobacteria in children with cystic fibrosis: isolation, prevalence, and predictors.

Background: Screening for non-tuberculous mycobacteria (NTM) is recommended for adults with cystic fibrosis (CF). The relevance of this organism in North American pediatric CF patients is unclear as there is limited NTM prevalence data for children. We aimed to determine the prevalence of NTM in children with CF from a single expectorated sputum and identify clinical predictors of NTM isolation.

Realities of expectorated sputum collection in the pediatric cystic fibrosis clinic.

Objectives: To determine the proportion of pediatric patients with cystic fibrosis who do not produce expectorated sputum during routine ambulatory clinic visits and to identify clinical predictors of these patients.

Design: Cross-sectional study.

Setting: The cystic fibrosis clinic at The Hospital for Sick Children, Toronto, Ontario.