Airway responsiveness

Our study confirms the finding of one other recently reported comparison of parent- and child-completed questionnaires in another country and in older children. Among 271 13-to 14-year-old children in Germany, wheezing in the past year was reported on both questionnaires in 12.1%, by the parent but not the child in 8.3%, by the child but […]

The relatively low sensitivity of the methacholine challenge with regard to a history of milder wheezing symptoms (not diagnosed as asthma) requires comment. Wheezing might occur in association with variable airflow limitation when methacholine airway responsiveness is normal if the stimulus to wheezing is strong, such as a severe reaction to an allergen or chemical […]

This study has documented in a small pilot sample the occurrence of symptoms consistent with asthma and of airway responsiveness to methacholine among a sample population of children aged eight to 10 years. The group of 229 children undertaking all investigations was representative of the full cluster sample selected. The estimated prevalences of both physician-diagnosed […]

These analyses were repeated using only symptoms reported as current, ie, occurring in the past 12 months before testing (Figure 2). Parent-reported physician-diagnosed asthma with current symptoms was highly correlated with airway responsiveness (Figure 2A; P=0.038), although wheezing not diagnosed as asthma was not (P=1.0). There were no significant increases in area under the ROC […]

In an attempt to define better the relationships between sensitivity and specificity of methacholine responsiveness and parent-reported and child-reported respiratory diagnoses and symptoms, ROC curves were developed by determining the numbers of children with PC20 values below successively lower cut-points reflecting increasing levels of airway responsiveness within each symptom strata. A parental report of physician-diagnosed […]

Relation between symptoms of asthma and airway responsiveness: Of the 21 children with physician-diagnosed asthma challenged with methacholine, 13 (62%) had PC20 <8 mg/mL. Of 61 children with a parental report of wheezing, 31 (49%) had PC20 <8 mg/mL. On the other hand, of 78 who showed methacholine hyperresponsiveness as determined by PC20 <8 mg/mL, […]

Symptoms reported by parents: Physician-diagnosed asthma was reported by parents for 26 children (14 male) or 9.0% of the study population (Tables 2,3). Of these, 19 had had asthma symptoms in the past 12 months, and 11 had had four or more episodes during that time. The parents of 74 children (44 male) reported their […]

Class lists from the seven randomly selected schools identified 309 children in grade 4. Four children were excluded because their parents could not understand the study sufficiently to give informed consent, and a further six parents refused consent for any part of the study. Nine children had moved from the selected school before the study […]

Methacholine inhalation challenges were undertaken in all consenting children by using Wright’s nebulisers with an outputof0.13 mL/min and particle size 1.5 ^m aerodynamic mass median diameter. The child inhaled nebulized normal saline followed by increasing concentrations of methacho-line chloride by tidal breathing for 2 mins using a face mask. Spirometry was undertaken before, and at […]

The sample: Following discussions with boards of education in and around Hamilton, Ontario, approval was obtained for a pilot study of the prevalence of asthma and airway hyperresponsiveness in 300 grade 4 children in East Halton, 40 km southwest of Toronto. Seven of 18 elementary coeducational schools in this region were randomly selected, and all […]