Differences in respiratory symptoms and pulmonary function in children in 2 Saskatchewan communities.
BACKGROUND
Asthma prevalence is known to vary among different geographical regions both nationally and internationally. However, there is limited understanding of the nature of differences within geographical regions.


OBJECTIVE
To evaluate the prevalence of asthma in 2 prairie communities and differences in the patterns of respiratory symptoms between the communities.


METHODS
A cross-sectional questionnaire survey was sent through schools in Estevan and Swift Current, Saskatchewan, to parents of 2,231 children in grades 1 to 6. Asthma prevalence was determined by questionnaire report of physician-diagnosed asthma. Pulmonary function tests (PFTs) using spirometry were conducted in children in grades 1 to 4. To evaluate respiratory morbidity without the use of a diagnostic label, similar comparisons were made between communities for respiratory symptoms.


RESULTS
The overall response rate to the survey questionnaire was 91.3%. The prevalence of ever asthma in Estevan was 21.4% (95% confidence interval [CI], 20.1%-22.7%) compared with 16.2% (95% CI, 15.1%-17.3%) in Swift Current. A higher proportion of girls in Estevan (19.7%; 95% CI, 17.9%-21.5%) compared with girls in Swift Current (12.5%; 95% CI, 11.1%-13.9%) reported a history of asthma. There was no difference found between towns for boys. These findings were supported by findings for respiratory symptoms, including wheeze and cough. For both boys and girls, the forced expiratory flow at 25% to 75% of forced vital capacity and the ratio of forced expiratory volume in 1 second to forced vital capacity were lower in Estevan compared with Swift Current.


CONCLUSIONS
Differences in the distribution of childhood asthma can be found within regions. These results are strengthened by PFTs and cannot be fully explained by diagnostic biases.
Rennie
Donna C
DC
College of Nursing, Institute of Agricultural, Rural and Environmental Health, University of Saskatchewan, Saskatoon, Canada. rennied@sask.usask.ca
Lawson
Joshua A
JA
Cockcroft
Donald W
DW
Senthilselvan
Ambikaipakan
A
McDuffie
Helen H
HH
D001249:Asthma / Q000453:epidemiology* / Q000503:physiopathology*; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D006306:Health Surveys; D006801:Humans; D008168:Lung / Q000502:physiology*; D008297:Male; D015995:Prevalence; D012129:Respiratory Function Tests; D012130:Respiratory Hypersensitivity / Q000503:physiopathology; D012140:Respiratory Tract Diseases / Q000503:physiopathology*; D012525:Saskatchewan / Q000453:epidemiology; D011795:Surveys and Questionnaires