Prevalence of asthma symptoms among 13-14 years old children in Birjand

Background: The risk of asthma prevalence has increased dramatically in children in
developed countries over the last three decade. The studies in developing countries have also
detected an increased prevalence. There is limited data from ISAAC study in Iran. Considering
ISAAC Study in Birjand in 1996, this study will reveals prevalence and time-trend of asthma in
Birjand.
Methods and Materials: For this purpose, a descriptive study was conducted. By simple
sampling, 3540 subject aged 13-14 years, including all from 22 intermediate level schools were
recruited for study using the International Study of Asthma and Allergies in Childhood
(ISAAC) from across Birjand city in 2002. Subjects were studied by video questionnaires. In
this method, the audiovisual presentation of the questionnaires included five scenes of asthma
symptoms in different situation. After each scene, the subjects ticked the answer whether or not
they experienced the same problems with breathing as the child in video. Analysis of data was
done using descriptive analytic and chi-square test.
Results: There were 3,540 students including 49% females and 51% males from 22
intermediate schools. One girl school refused to participate in study. The amount of missing
data was less than 1% each scenes. The prevalence rates in video questionnaire for any wheeze
ever in life, and current wheeze in last 12 months, were 18%, 10.1% respectively. The
prevalence of night cough in last 12 month, speech limiting wheeze at rest in last 12 month,
and one or more time a month of any wheeze was 4.5%, 2.2% and 7.4% respectively. The
prevalence of any wheeze ever in life, and current wheeze in last 12 month was higher in
females compared with males (P<0.001).
Conclusions: The results of this study on asthma symptoms, suggest an increase in the
prevalence of asthma symptoms in Birjand when compared with prior study in this region. The
results are suitable for comparison with other ISAAC studies. It also represents a baseline for
further analytic epidemiological research.